Why is Snake Island considered to be one of the most dangerous place on Earth

Ilha da Queimada Grande in Brazil is known as one of the world's deadliest islands because of its highest concentration of venomous snakes. The snakes on this island became trapped and the rising sea levels covered up the land that connected it to the mainland. This Island is  just 33km off the coast of Brazil near Sao Paulo.  

                          

Do humans lived on this Island: From 1909 - 1920s, a few people did lived on this island, in order to run its lighthouse. But according to another local tale, the last lighthouse keeper died along with his entire family when a cadre of snakes entered into his home through the windows.

Why the snakes on this Island are so venomous: This Island is the only known home for Golden Lancehead snake and this snake is one of the most venomous vipers in the world. The snake's venom is said to be 3-5 times stronger than that of any mainland snake. 

One poisonous bite from the Golden Lancehead pit viper is enough to kill a person within a few hours. It's fast-acting venom will burn through flesh and cause its victim to bleed to death.

Over 11,000 years ago, the sea levels rose enough to isolate Ilha da Queimada Grande from  Brazil, leaving the all species of snakes alone on the island to evolve into what they have become today.

Do anyone visit the Island for experiments: The Island is so dangerous that people are banned to visit the snake island. However, Brazilian authorities give permission to only few scientists to visit this island every year and Navy patrols make sure no other human get close.