Snakes on your left.
Snakes on your right.
Giant cockroaches behind you.
And in front of you, the open sea.
It's difficult to get to this island
in the first place.
But it's almost impossible to get out alive.
About 33 km (20 mi) off the coast of Brazil,
near the state of Sao Paulo,
there's a place so dangerous
that it's uninhabited
and closed to visitors or tours.
Ilha da Queimada Grande,
also known as Snake Island,
is only 430,000 m2 (106 acres).
But it is home to a lot of danger.
It’s estimated that there is at least
one snake per m2 (1.2 yd2)
and about 4,000 of them
are golden lancehead pit vipers.
They're one of the deadliest snakes
in the world.
This place is feared
even by local residents,
who tell stories of people
going to the island
but never coming back.
Unless you're in charge of fixing
this lonely lighthouse,
there's no reason for you
to go to Snake Island.
But if you arrive there by accident,
how could you survive?
If you go sailing or fishing near the Island,
you'd better keep your distance.
Snake Island is surrounded by rocks.
So it is dangerous to swim near it,
and it could break your boat.
In late February of 2019,
a small fishing boat with six men
got caught in a storm.
It began sinking near Snake Island.
Knowing exactly which island
they were near,
four of the men decided to swim to shore.
The other two remained in the boat,
choosing to die on their own terms.
The four men were on the island
for three days,
they stayed on the beach
without entering the forest.
For three days,
they drank rainwater and ate bananas
they found on the edge of the forest.
Then they spotted a boat going near
the island and quickly swam to it.
The boat picked them up
and delivered them to the nearest
emergency room on the coast.
Lethal vipers are not the only threat
on Snake Island.
There are many nonvenomous snakes,
giant cockroaches
and locusts that cover the island.
If you're anywhere on Snake Island,
you should regularly check for
these not-so-little critters.
And try to avoid them the best you can.
On the other hand,
if you have a strong stomach,
they could save you from starving.
Cockroaches are safe to eat
and a good source of protein
and essential amino acids.
Bon appetit!
If you're stuck on this island,
you will have to face the snakes.
Try to find a stick.
It will help you fight the snakes off
and prevent them from biting you.
If you get bitten,
prepare to suffer.
Since the golden lancehead pit vipers
on the island evolved naturally,
they developed a venom
up to five times stronger
than a regular lancehead viper's.
This powerful venom causes
severe physical complications,
including kidney failure,
brain hemorrhaging
and intestinal bleeding.
It also can cause muscle tissue to die.
So you're going to feel
as if your skin is melting.
Take off any rings, watches and bracelets,
as they could become
really hard to remove
if an arm begins swelling.
If you have an EpiPen,
use it to treat symptoms of anaphylaxis,
like swelling of the face, mouth or throat,
hives or difficulty breathing.
The only way to increase
your chance of surviving
is with medical help,
which takes us to our next step.
Only biologists and researchers
visit the island.
They study the
golden lancehead pit vipers.
And the Brazilian navy
visits once a year
to maintain the lighthouse,
which has been automated
since the 1920s.
The government requires
that every team that visits the island
includes a doctor.
If a golden lancehead bites you,
you have a 7% chance of dying.
Being treated by a doctor
can reduce those chances to 3%.
Despite the island's dangerous snakes,
wildlife smugglers,
also known as
biopirates,
have made frequent stops
to trap and sell the snakes.
A single golden lancehead pit viper
is worth about $10,000 - $30,000
on illegal markets.
And since this is the only place
where they exist,
the golden lanceheads
are listed as endangered
on the International Union
for Conservation of Nature's Red List.
You escaped Snake Island alive,
but it's not the only dangerous place
around South America.
You could end up in the Amazon,
surrounded by these bloodsucking fish.
And if you're not careful,
they might try to swim up your urethra.
Want to know how to stop them?
Find out here.