WHAT IS INSIDE MADAGASCAR CRATER.

An island off the coast of Africa.

It’s one of the most biologically diverse places in the world.

Almost all of its plants and animals aren’t found anywhere else on Earth.

And when we looked at it from space,

we saw a spot.

A massive dark circle,

almost perfectly round,

over thirteen kilometers in diameter,

and big enough that roads are diverted on either side of it.

Looking at it from the side, we could see

it was a mountain.

And if you zoomed all the way in, you could see a village

nestled in the crater at its center.

8 kilometers from the closest labeled town on Google Maps.

Isolated in a remote part of a remote region of a geographically isolated country.

It looked like it could have been there for generations.

But if you looked backward through time …

… each year …

… it gets smaller and smaller …

… and before 2008, there was no one there at all.

I wanted to try to answer one question:

Why did these people move to such

an incredibly isolated place?

I was really starting from zero here.

I didn't know anyone in Madagascar.

I didn't know that much about Madagascar.

But the question was: could we get in touch with the people living here just by using the internet?

The closest location tags were on the edges of the mountain: a butcher shop, a playground,

and a historical landmark.

But none of them were real — they all seemed to be random references to the popular Japanese

manga and anime series Attack on Titan, written in Russian.

The ones that did look real — churches, hospitals, schools — didn’t have much

of a presence on the internet.

So we looked at content that had been geotagged nearby.

First on Twitter: using the coordinates of the village, and a search radius.

Until finally at 12 kilometers away …

… we found someone.

A nonprofit worker who had posted from a nearby village in 2014.

We asked if he knew about the village on the mountain.

But he never got back to us.

On Instagram, we looked for pictures tagged in the nearest town, Antaniditra

and found an aid organization that had posted pictures taken there.

We asked, but they didn’t know.

They’d never actually been on the mountain at all.

And finally we looked at geotags on YouTube.

And there was a video.

Geotagged right next to the village on top of the mountain.

But, then…

It was just more Attack on Titan stuff.

Also written in Russian.

After a while, it felt like the internet alone was not going to tell us very much.

So we started reaching out to experts who had worked in Madagascar.

Experts in agriculture.

Madagascar is a country of almost 29 million people: slightly more than Australia, slightly

fewer than Texas.

A majority of the country's population — over 60 percent — lives in rural settings a lot like this one.

But this village was particularly remote.

If you zoom out, the closest major city is a place called Tsiroanomandidy.

18 kilometers away, with a population of over 44,000.

At this point in the process, it felt like we might need to take a more drastic approach.

Maybe we could hire someone to make the journey up the mountain to the village itself.

Someone in Madagascar.

That’s how we met Lalie.

Hi Christopher.

Lalie runs a production company in Madagascar, in the capital city of Antananarivo.

She was down to make the trip.

She started to gather a crew…

… make local contacts …

… and figure out how to get from Antananarivo all the way here.

They weren't exactly sure yet how they'd get up to the village.

Or how they’d establish contact once they got there.

Madagascar and India happened to be located beneath this really deep-seated mantle source,

they're called plumes.

When that plume reaches the planet’s crust, it forms a hot spot.

As Madagascar moved over the hotspot, it burned a hole through Madagascar

and produced all the volcanics all over the island.

As Madagascar’s continental plate continued to move,

those volcanoes were eventually cut off from the hotspot.

And without a heat source, they cooled and collapsed.

And then you're left with the plumbing system that was underneath that volcano.

So that’s what we were looking at: the collapsed remnants of a volcano formed by a hotspot

that had broken up apart Madagascar and India.

At this point, I had no idea what any of this might have to do

with the village we could see on Google Earth.

But right about then, we heard back from another Malagasy expert we’d emailed.

He sent us a link to mindat.org — this is like the Wikipedia of minerals and mines ...

… and it had a page about the mountain.

Including its name: The Ambohiby Massif.

Finally. We knew the name of this mountain that had been unlabeled

on every other map we’d seen so far.

And we could search for it.

We found maps from 1899, 1903, and 1916,

where the Ambohiby was always labeled as a lush forest …

… the only one for almost 100 kilometers.

That definitely didn’t seem to be the case anymore.

But maybe these old trees were a clue.

We kept looking.