[ambient music]
- Tonight, two of the world's most mysterious monuments.
- People have been trying to decipher Stonehenge
for literally hundreds of years.
- Easter Island is home
to not just one sacred stone structure,
but over 900 of them known as the moai.
- [Dennis] To this day,
no one knows how they were built or why.
- We can't stop trying to unravel their mysteries
'cause they still have a lot to teach us.
- What secrets can these
intriguing structures reveal about
the people who first created them so many centuries ago?
- This tells him exactly who built Stonehenge,
and it is not who anybody expected.
- This could be the key
to unlocking the mystery of the moai.
- These sacred objects have inspired all
for thousands of years.
Now the remarkable stories
behind history's most compelling "Holy Marvels".
[ambient music]
Salisbury Plain, England,
home to one of the world's most mysterious sites,
a circle of towering stones,
whispering of ancient societies and arcane rites.
Known as Stonehenge,
this imposing monument has dominated the imagination
of archaeologists and visitors for centuries.
- The name Stonehenge is thought
to come from the Old English or Saxon word,
stan-hengen, which means stone hanging
because it kind of resembles
what gallows looked like in the Middle Ages.
You had two uprights with a cross beam.
Today there are 52 stones remaining at the site,
laid out in two concentric circles,
but scientists think that they were originally
about 80 of them.
And the stones themselves, massive.
They're 13 feet tall and some weigh up to 25 tons.
- Standing next to these stones is just awe inspiring.
It makes you feel so small and insignificant
and it raises the obvious questions.
Who built this monument and how and why?
- No one has ever found anything resembling written plans,
no stone tablets, no papyrus, no cave drawings,
nothing that can serve
as an instruction manual or a backstory
to explain how this happened.
- [Dennis] The first known speculation on the origin
of Stonehenge comes from a book
written in 1136
by Geoffrey of Monmouth
called "The Histories of the Kings of Britain".
- Geoffrey of Monmouth's book
isn't what you would exactly call
an accurate, verifiable history text,
but there are lots of historical facts
that are embedded in there alongside other more legendary
material like the stories of King Arthur
or the Knights of the Round Table or Guinevere
or the famous wizard, Merlin.
- [Dennis] According to Geoffrey's account,
Merlin plays a surprising role in building the monument.
- Around the fifth century,
the area of Stonehenge is inhabited by people
that are known as Celtic Britons,
but an army of Germanic invaders called the Saxons arrives
and tries to wage war and conquer the land.
A meeting is called between the two sides,
but it turns out the Saxons aren't really there to talk
and they murder hundreds of the Britons.
[dramatic music]
- [Dennis] Geoffrey claims the structure we know today
as Stonehenge is commissioned to honor the dead.
- It's a giant grave marker
that was built in the fifth century A.D.
Now that seems plausible,
but the rest of the story does not.
- To build this grave monument,
the king of the Britons, Ambrosius,
asks the wizard Merlin for help.
Merlin instead decides to steal a monument
that already exists.
It's called the Giant's Ring.
- The Giant's Ring is a set of stones in Ireland
said to be located at Mount Killaraus,
and it's believed that they were set up there for purposes
of ritual healing.
- According to Geoffrey of Monmouth,
Merlin and 15,000 men sail to Ireland
and battle the Irish king, Gillomanius, for the stones.
Merlin and company win the war
and with the help of a little magic,
they bring the stones back to Salisbury Plain.
- Whether or not you believe in Merlin or magic,
this theory was believed to be the truth
for hundreds of years.
- [Dennis] While Geoffrey's story seems fantastical,
he was right about one thing.
- The stones themselves must have been imported,
maybe not from Ireland,
but there's nothing like them geologically
in the immediate area.
- [Dennis] Over the next 400 years,
the origin of the stones generates numerous theories.
- In the late 1500s,
a British antiaquarian named William Lambarde proposes
a source for these stones.
Now, Lambarde believes that they come, not from Ireland,
but from a quarry in Marlborough Downs,
which is 20 miles away from Stonehenge.
- His method is somewhat unscientific.
He just spots some stones in Marlboro
and thinks these look an awful lot
like the stones over at Stonehenge.
To be clear, he's not a geologist,
but later geologists are able to match the stones
and prove that his theory is correct.
This is hard to believe at first
because before the advent of trucks, trains, cars,
any sort of transportation device with a wheel,
when these multi-ton monsters had to be transported
by hand, 20 miles is quite an imposing distance.
These stones might as well have come from the moon.
- There's another wrinkle.
Lambarde realizes that there are actually two types
of stone at Stonehenge.
The larger ones are a type of rock called sarsen,
and that's what's at Marlborough Downs.
There are also smaller stones of a type known as blue stone
because it looks kind of blueish in color
when it's broken apart.
And neither Lambarde nor anyone else can find
anything like these blue stones in the entire region.
- While these discoveries are fascinating,
they do not aid us in figuring out
who precisely built Stonehenge.
- [Dennis] It's something that captivates King James I,
so he hires a top surveyor in 1620
to unravel the mystery.
- Inigo Jones is considered the first major architect
of modern England.
He's known for applying beautiful ancient Greek
and Roman rules of proportion and symmetry to his work.
- [Dennis] Jones takes this same approach
when examining Stonehenge.
- He spends a great deal of time
poring over historical building techniques
of other societies that have inhabited the area,
and he decides that the only thing that adds up,
the only people who once lived here
who could have built this thing are the Romans.
- [Dennis] If Jones is correct,
Stonehenge could be much older than Geoffrey
of Monmouth proposed.
- The Romans invade the British Isles way back
in about 50 B.C.
and they stay until the Celtic Britons kick them out
around 410 A.D.
So the Romans very clearly predate the rule of the Britons.
There's actually no real overlap.
- In a book called "De Architectura" by Vitruvius
from about 30 B.C.,
Jones finds Stonehenge resembles the layout
and proportions of Vitruvius' temple designs.
[tense dramatic music]
Because it was built without a roof or an enclosure,
Jones concludes that it must have been built
to worship the sky god, Caelus.
- But when Jones' theory is published,
it's pretty immediately dismissed.
Take a look at any Roman building
and you can see that it's a lot more polished
and detailed than Stonehenge.
So despite the King's backing,
pretty much nobody believes that it's the Romans,
but who else could it possibly be?
[dramatic music]
- For more than 700 years,
the mystery of who built Stonehenge,
and how, confounds scientists and historians.
- In the 1800s, we have a series of archaeologists
doing excavations around Stonehenge,
and during these digs, they're finding all sorts of things,
charred wood, bits of antlers, and even Roman pottery.
It's all kind of unremarkable,
fueling just one origin theory after another.
- [Dennis] Then in 1862,
researcher John Lubbock takes a closer look
at these various artifacts.
- Lubbock finds something that, to him,
is truly astonishing,
cremated human remains.
- Now to a lay person, this might not mean too much,
but to Lubbock, this tells him exactly who built Stonehenge,
and it is not who anybody expected.
- [Dennis] According to Lubbock,
cremation hasn't been practiced in this area
since the Bronze Age.
- That means that there was a previously unknown
civilization living right here of Bronze Age people,
and that's who built Stonehenge.
- It's a major discovery not just in the history of England,
but a huge leap forward in our understanding of Stonehenge.
- [Dennis] The Bronze Age in Britain spans
from approximately 2500 to 700 B.C.
- It appears that somewhere
around 2400 B.C.,
the area around Stonehenge
sees the arrival of a group
that's come to be known as the Bell Beaker people,
named for their inverted
and highly ornate bell beaker drinking vessels.
But the Beakers are significant for another advancement
when it comes to Stonehenge.
They figured out how to melt tin and copper alloy,
mix them together, and to create something new, bronze.
- Lubbock continues to excavate,
and sure enough, he finds tools made from bronze.
This indicates that Stonehenge was built much earlier
than people had previously understood to be built.
- [Dennis] If Lubbock is right about who built Stonehenge,
the next question is how?
- Before Lubbock, basically no one
in the scientific community could have
imagined that Stonehenge dates back so far.
They believe that people of the Bronze Age
were so incredibly primitive,
they would've lacked the skills
to pull off such an incredible feat of construction.
- How could barbarians
and savages transport 20-ton stones
from 20 miles away and hoist them up?
- [Dennis] Initially, one particular idea prevails.
- Some speculate that the builders
could have dug small holes around the perimeter
and inserted long wooden poles
in a triangular A-frame shape.
Then they could pass long ropes over the frame,
creating leverage. Get a big enough group of people
on the other end of that rope
and they should be able to pull a stone into position.
- This theory is supported by the fact that a ring
of 56 small holes is discovered
around the outside of Stonehenge.
They're called the Aubrey Holes,
named for the archaeologist who found them, John Aubrey.
- [Dennis] But in 2022,
British archaeologist, Mike Pitts,
argues this is impossible.
- Pitts has directed excavations at Stonehenge.
He's also been an editor
of the British Archaeology Magazine.
In 2022, he writes a book called "How to Build Stonehenge"
and it's a fascinating new take
on constructing the monument.
- According to Pitts,
the problem with the A-frame theory
is that it imagines each stone at Stonehenge
was put in place by itself with no other stones around it.
And this of course, can't be true.
Pitts reminds us that Stonehenge
was a construction site, okay,
with a whole set of stones being raised in a sequence.
You can't set them up using the Aubrey Holes and A-frames
because they'd just being each other's way.
- [Dennis] Instead, Pitts offers another explanation.
- Pitts thinks that the stones were brought
near their final spots and then rocked back and forth
with levers on either side.
Each time one side was lifted,
they'd carefully place smaller rocks under it to prop it up
and they'd keep rocking it up and propping it up higher
and higher until it was nearly upright,
at which point a quick tug on a rope could easily pull it
into a vertical position.
- Pitts' suggestion is definitely possible,
but unfortunately we can't prove it,
and to this day, nothing has been found
that can tell us for sure.
- [Dennis] While we might never know
exactly how it was built,
experts are determined to figure out why.
In the early 1700s.
an English scholar makes a groundbreaking observation.
- The antiquarian physician Freemason, William Stukeley,
discovers that actually Stonehenge
is aligned with the sun.
- If you stand in the right place,
the space between the central megalith perfectly frames
the sun's movement on two days of the year,
the summer solstice and the winter solstice.
So, it seems that Stonehenge is accurately built
to highlight the longest and the shortest days of the year.
Many scholars speculate that what Stonehenge is,
is a solar calendar, a method of timekeeping.
- Later researchers have noted that the number
of stones correspond loosely with a 30-day month
and certain stones could mark the start
of three 10-day weeks.
This is probably the most popular theory on
why Stonehenge was built.
- Visitors still travel to the site to witness the sunrise
between the two great stones on each equinox.
- The alignment with the sun
was almost certainly done on purpose,
but that doesn't mean that it is the purpose, right?
Correlation isn't causation.
Just because you paint your house blue
doesn't mean you worship the sky.
- [Dennis] It also doesn't explain why there are so many
burials around the area.
- In 1919, 58 sets of human remains are found.
This definitely suggests
that the monument wasn't just a way of tracking the sun.
- [Dennis] In total, more than 200 sets of remains
have been uncovered at Stonehenge.
- There's even evidence Stonehenge might have been
some kind of primitive hospital.
Two skulls found at the site show evidence
of rudimentary surgery.
But again, this might just be a coincidence.
Remember, correlation doesn't equal causation.
- What's so neat about Stonehenge though,
is that there are still so many
new discoveries being made regularly.
Almost every year we advance our understanding of it,
and so the question
of why it was built still seems like something
that we may eventually be able to answer.
In fact, one very recent discovery may have brought us
closer than ever to understanding Stonehenge.
[dramatic orchestral music]
- [Dennis] Despite dozens of investigations
all using the most modern technology,
the true purpose of Stonehenge
remains a mystery until 2021
when one enterprising archaeologist finally answers
a key question about the blue stones.
- So for at least 400 years,
people have known there are two different types
of stones at Stonehenge.
There's the sarsen stone,
which we know comes from a quarry about 20 miles away,
but no one knows where the blue stone comes from.
[dramatic suspenseful music]
- [Dennis] For decades,
scientists work to figure out their origin.
- First in 1923,
geologist, H.H. Thomas,
finds a whole bunch of this type of stone,
a perfect match in fact,
but where he finds it makes no sense whatsoever.
- He proposes that the blue stones come from
the Preseli Mountains in Southwest Wales.
It's a whopping 150 miles
away from Stonehenge.
- Several later archaeologists
and geologists continue the work of H.H. Thomas,
and eventually modern geochemical analysis proves
that he was right.
These stones definitely came from Wales.
- [Dennis] But the exact location is still unknown.
- Then in 2021, archaeologist, Mike Parker Pearson,
is able to confirm the exact quarry in Wales
that the blue stones came from.
That's when he finds the final missing piece
of the puzzle, quite literally.
- Near this quarry, there are the remains
of a dismantled circle of these same blue stones,
and like Stonehenge,
it's aligned with the movement of the sun.
And incredibly, Parker Pearson finds a chip
of blue stone left behind when it was dismantled
and it fits perfectly
into one of the blue stones at Stonehenge.
- Now we know what happened.
This society didn't just randomly start
building at Stonehenge.
They migrated there.
Many centuries before, they lived in Wales
where they were already making primitive stone circles,
and these circles were aligned with the movement of the sun.
- [Dennis] Parker Pearson determines that this group
of people decides to leave the area around 3000 B.C.
- And they dismantle
and take their sacred stone circle with them.
They then migrate to Salisbury Plain.
- Once you combine Parker Pearson's discovery
with a few others, suddenly it opens up the idea
that there might have been multiple different purposes
for Stonehenge throughout the years.
Stonehenge wasn't just built from scratch
the way we see it looking today.
It's a site that has evolved
and changed dramatically over the course of 5,000 years.
- [Dennis] In fact, it doesn't even start
with stones at all.
- In 1966, Lance and Faith Vatcher
discover three post holes in the Stonehenge car park
that when analyzed,
date back to between 8500 and 7000 B.C.
In this spot three wooden tree trunks were raised
by some early mesolithic hunter-gatherers.
This tells us that a small group of people was beginning
to think of this as a sacred place.
- The site grows in popularity
and other societies start coming to visit.
Around 3900 B.C., we have evidence of the area being used
as this massive meeting place.
Archaeologists have discovered remnants of a feast
between a culture of hunter-gatherers
and a group of farmers.
- Now, Stonehenge has gone from kind of an outdoor chapel to
a great place of multicultural gathering and unity,
but there aren't any stones yet.
- [Dennis] At least not for another 900 years.
- As Mike Parker Pearson discovers,
a group of people show up at around 3000 B.C.
and they bring their stones from Wales with them.
- The locals, they welcome these folks with open arms.
They say, "Please, put your sacred stones right here."
And they all work together
to build a circular earthen enclosure surrounded by a ditch.
And in the ditch, they erect 56 posts.
- And just like they did in Wales,
the migrants make sure to align the circle to the sun.
Now, Stonehenge is also an astronomical calendar.
- [Dennis] As time moves on,
Stonehenge also becomes a significant place of burial.
- As many as 240 burials have been discovered
at Stonehenge so far,
but there may be more.
It makes sense that such a sacred place in life
would also be sacred in death.
So now it's a calendar, a holy gathering place,
a shared construction project
between two cultures, and a cemetery.
[soft contemplative music]
And around 2500 B.C.,
the locals decide it's time to give Stonehenge an upgrade.
- [Dennis] This is when the 80 massive sarsen stones
are set up in the familiar circular formation
that still captivates visitors today.
- Researchers think that the end result
wasn't the whole point of Stonehenge.
The point was in the process.
Stonehenge was like the ultimate community service project
bringing people together, which it's still doing today.
[dramatic music]
- Even after thousands of years,
Stonehenge continues to confound and intrigue us.
Some 8,000 miles away,
a very different society
has left an even stranger puzzle to solve.
[dramatic music]
- Easter Island is home
to not just one sacred stone structure,
but over 900 of them known as the moai.
The island is around 2,000 miles off the coast of Chile.
Some consider it the most remote island in the world.
In fact, the nearest place where other people live
is Pitcairn Island about 1,200 miles away.
- In the early 18th century,
European explorers stumble upon it completely by accident.
- [Dennis] On August 1st, 1721,
a team of Dutch sailors led by Jacob Roggeveen
sets out on a mission sponsored
by the Dutch West India Company.
- They've been tasked to find a place
called Terra Australis,
which is a hypothetical continent,
which is rumored to exist at the time.
And even though it appears on maps between the 15th
and the 18th century, no one's actually seen it.
- So Roggeveen sets off to find Terra Australis
and he doesn't because as we now know, it isn't real.
But he does find something incredible,
a remote and uncharted island.
And on that island, there's a mystery unlike anything
the world has ever seen.
[dramatic music]
- [Dennis] In 1722, Dutch explorer, Jacob Roggeveen,
sets foot on a remote unknown island
in the middle of the South Pacific.
- He lands on April 5th, which that year was Easter Sunday,
and so he names it Easter Island.
Roggeveen finds that Easter island is dotted
with several small village centers,
and all the people there seem to be from Polynesian descent,
so similar to the Samoans, Native Hawaiians.
And Roggeveen records
around 3,000 people living on the island
and they survive by farming things like bananas, taro,
sugar canes, they raise chickens.
- [Dennis] But there's something else besides people
and farms on Easter Island.
Something astounding.
- Roggeveen writes that the island features,
quote, "remarkable tall stone figures,
a good 30 feet in height."
These statues are massive.
Some weighing over 80 tons.
They're legless, humanoid torsos with oversized heads,
prominent noses and elongated ears,
and there are hundreds of them.
- Some stand up by themselves while groups
of others are lined up on what looks like stages
or altars near the shore.
Of course, naturally Roggeveen has some questions like,
what the heck are these things
and how are they built and why?
- So when Roggeveen asks the locals exactly
what these things are,
they tell him that they are moai,
and it sounds really exotic, like wow.
But as it turns out,
the word simply means statue.
- The islanders say the statues were made many generations
before these islanders were born
and that they represent the ancestors
who've come and gone before them.
But that's about all they know.
Most of their history has been forgotten or just lost.
- [Dennis] Nearly 50 years later,
other explorers also stumble upon these strange statues.
- Two Spanish ships visit in 1770
and their records state that the sailors were amazed by
what they called the standing idols.
- In 1774, famed British explorer, James Cook,
visits Easter Island.
This visit though, something's different.
He writes that some of the statues had been toppled,
and this wasn't the case just four years earlier
when the Spanish were there.
[tense suspenseful music]
- [Dennis] This new detail gives Cook a clue
about the statues' possible purpose.
- When Captain Cook arrives,
he notices that the moai are facing towards the village
away from the sea,
as if they're looking over and protecting the villagers.
- [Dennis] There is just one problem with this theory.
- Because some statues are toppled by 1774
and nobody else has been here,
this clearly tells us one thing, the islanders did it.
- [Dennis] Why would the locals purposely destroy
their own statues?
- Now, we think that instead of being a unified project
to protect the entire island,
these statues were meant
to protect just certain villages or regions,
and in fact, these regions may not have gotten along well.
- [Dennis] It takes nearly a century
for the next major breakthrough.
- In the late 1800s,
a lot more people start visiting Easter Island.
Christian missionaries come.
Peruvian slave traders come as well,
and they capture about 1,500 of the natives,
which is about half the entire population.
They also, sadly, bring smallpox and tuberculosis too,
which kills countless locals.
But amidst all this tragedy,
there's a new find,
about two dozen wooden objects
with pictographic glyphs carved across them in neat lines.
- So this is the language that we never knew existed.
It's called Rongorongo,
and it's similar to Egyptian hieroglyphics.
- Unlike at Stonehenge where we have no written record
as to how this was built,
this could be the key to unlocking
the mystery of the moai.
However, there's just one problem.
Among the people kidnapped
or killed on Easter Island
are the only people who can still read Rongorongo.
So as soon as the foreigners discover this language,
they also ensure that we'll never be able to read it.
It's a terrible irony.
- [Dennis] While many have tried to translate it,
all have failed.
But a common mythology
amongst cultural neighbors may offer valuable information.
- Many Polynesians believe that when properly constructed,
these statues could house the dead's mana,
described as a supernatural power that dwells
or lives in the head and in the hair.
It's possible that the Easter Islanders
don't just build the moai
to represent their ancestors,
but actually as vessels to hold their spirits, their mana.
- We can see on some of the moai to this day,
special attention is given to the top of the heads,
mainly in the form of a separate stone placed on top
that kind of looks like a hat.
Scientists theorize that these represent
a tribal chief's top-knot
or pukau where all their mana would reside.
- Polynesians also believe
that one's ancestors could come back in spirit form
and aid in times of need.
So why not build these giant
manafilled repositories for them?
Of course, this is all just speculation.
Until someone can translate Rongorongo
we'll probably never know if our guess is correct.
- [Dennis] Today, this remains the prevailing theory
on why the moai were built,
but it's far from the only mystery
surrounding these stones.
- It's good to ask why.
But the even more interesting question is how?
How the heck did they build these things in the first place?
- While evidence points to possibilities
for why the Easter Island statues are built,
no one is quite sure how they got there.
- It's also unclear when exactly the moai were built,
but our best guess is that they were making these statues
between about 1250 and 1500 A.D.
To put that date into some kind of perspective,
other things built in Europe during that time would include
the leaning Tower of Pisa and Paris' Sainte-Chapelle.
But Europeans when confronted by the moai
just can't comprehend them at all.
- When James Cook arrives in 1774, he writes, quote,
"We could hardly conceive
how these islanders wholly unacquainted
with any mechanical power could raise
such stupendous figures."
And Cook speculates that once the stone statues were carved,
they were raised a little at a time using scaffolding.
But Cook and other early visitors to Easter Island
stayed close to the coast.
- [Dennis] It isn't until much later in the 1800s
that the rest of the island is finally explored.
And what's uncovered only deepens the mystery.
- Three quarters of a mile
from the island's southeastern coast at the base
of a large extinct volcano,
explorers find even more moai.
But these ones are different.
They're works in progress.
They're partially carved
into the volcanic rock of the hillside.
- [Dennis] The quarry is called Rano Raraku.
It's rich in a type of rock called tuff,
made of compressed volcanic ash.
- The most surprising thing
which Cook and all the other previous explorers
never realized is that this is also
where all the statues were carved.
- So this changes the way we think about
the origin of the moai.
It used to be thought that they were built where they are,
but in fact, they were built at this quarry
and moved 11 miles to where they are now.
And so how did this happen?
How did these people move 30- foot statues that were 80 tons
11 miles across this island?
- [Dennis] The natives tell explorers of a local legend
that offers a surprising answer to this question.
- According to the lore,
the powerful ancient chiefs literally command the moai
to rise up and walk, and they do.
It's a cool story, but not super helpful
in figuring out what actually happened.
Scientists have been floating
all kinds of theories ever since.
- One idea is that they're pulled around the island
on wooden sleds.
Another suggests that the ancients could have placed logs
underneath the stones and simply rolled
them across the island.
It would be difficult, perhaps, but not impossible.
With enough people and enough trees,
they could potentially roll their statues
where they need to go.
- [Dennis] But when the Europeans land on Easter Island,
there are no trees.
- The island is completely devoid
of any kind of wood source to make these rollers.
Moving these statues seems impossible.
- [Dennis] Until the early 2000s
when a pair of American researchers
are eager to prove it was possible.
- Anthropologists Carl Lipo and Terry Hunt,
propose a new hypothesis.
The moai walked to their location after all,
but it takes a little bit more effort
than in the original story.
Lipo and Hunt suggest
that the statues are transported in an upright position.
Ropes are attached to the heads of the statues,
three of them to be exact,
one on each side and one to the back.
- [Dennis] Then a team of people is assigned
to handle each rope.
- They walk the statue down the hillside,
alternately pulling from one side to the other
as the statue walks its way down.
From a distance, it would appear that the moai are walking.
- [Dennis] In 2012 to prove their theory,
Lipo and Hunt decide to recreate the process.
- They make a replica moai as close to the real thing
as humanly possible.
They get a team of volunteers, attach the three ropes
to the replica's head,
and they begin to pull.
And guess what?
- Two, three.
- The moai walks.
Now this doesn't prove that they used this exact method,
but it works.
It doesn't require too much manpower,
and you don't need trees either.
And as a bonus, it fits in really neatly with the legend.
[expansive dramatic music]
- As we can see, finding the quarry at Rano Raraku
does unlock some new answers and theories,
but it also raises another huge question.
After all this hard work on the moai,
why did they stop?
- [Dennis] The giant moai of Easter Island
offer many mysteries,
but perhaps the most intriguing isn't about how
or why they were made,
but why the islanders stopped building them.
- Now we know that these imposing statues
hold great cultural significance,
and the natives clearly spent massive amounts of time
and effort to craft and move them.
But when their quarry is discovered,
it's obvious that many moai were in progress
and never completed.
There are stone tools littered about,
and it looks like the work was abandoned quite suddenly.
They spent hundreds of years on this project, and then what?
One day they randomly get up
and walk away and just forget all about it?
- [Dennis] Since discovering the deserted quarry
in the mid 1800s,
researchers have been trying to find answers.
- One of the first theories emerges in the early 1900s.
It's originally proposed
by British engineer, James Churchward.
Churchward believes that Easter Island
actually wasn't an island to begin with.
- He claims that it was part
of a former large continent called the land of Mu.
He believes that Mu was once a large Pacific Ocean
continent nearly three times the size of Australia.
[lava explodes]
- A great series of earthquakes
and volcanic eruptions ultimately sink
nearly all of Mu beneath the ocean,
leaving only a few small islands behind,
such as Easter Island.
So that's why they stopped building the statues.
They were hit with the largest
natural disaster in human history.
- Today we know that there's no such continent,
but in the 19th century,
people believed that there was a land called Mu.
- [Dennis] Other theories are less fanciful,
but equally tragic.
- What we generally see with empires or civilizations
or even communities that decline over time
is that it's rarely a single event.
And so in the case of the inhabitants of Easter Island
and the building of the moai,
it might not have been one thing that caused that to end.
It could have been a whole host of factors.
- Problem number one,
the natives cut down all the trees.
While the island is treeless when the Europeans arrive,
soil and pollen analysis has proven
that it was completely forested as late as 1250 A.D.,
which is about when we think the islanders first arrived.
- [Lynne] No trees means no moisture in the soil,
and no moisture means no crops.
So this would've made things tough on the population.
- It's hard to spend much time carving
and moving giant statues when you're too busy fighting
over food with your neighbors.
- [Dennis] This shift in priorities
might also extend to their belief system.
- By the time the Europeans arrive,
the natives don't care much about the statues,
and instead practice something known as the Birdman cult.
It's the worship of the migratory seabirds
that would come to the island,
with a particular importance placed on their eggs.
- When you're faced with a starving, declining population,
maybe the statues lose their meaning.
After all, you can't eat them.
The birds and their eggs were some
of the only nutritious food available.
- Eventually, it seems the natives
became angry about the moai, even resentful.
Remember when James Cook arrives,
he finds that some of them
have been toppled over, broken apart.
Well, this practice continues.
As war and slave traders
and lack of resources reduce
the population further and further,
they keep knocking down their statues.
- Were they angry that the building of the moai caused them
to deplete all their resources?
Or maybe were they angry
that the moai failed to protect them?
- [Dennis] By 1868, every single moai has been toppled.
- Today, about 50 moai have been put back into place.
They attract up to 150,000 visitors per year,
which injects $120 million
into the island's tourism economy,
which sustains 75% of the population.
Seems like once again, the moai are doing the job
for which they were originally intended,
protecting and providing for the people of Easter Island.
- These larger-than- life sacred structures
like Stonehenge and the moai,
they're literally ancient history written in stone.
And we can't stop trying to unravel their mysteries
'cause they still have a lot to teach us.
- While we may never know all the secrets hidden
in Stonehenge or on Easter Island,
we can still marvel at the ingenuity
of our ancient ancestors.
I'm Dennis Quaid.
Thanks for watching "Holy Marvels".