20. Snake Island, Brazil
Ilha da Queimada Grande (a.k.a Snake Island) is a tiny island off the coast of Brazil. Snake Island is home to the venomous golden lancehead snake (Bothrops insularis) which has an incredibly lethal venom known to cause more human mortalities than any other group of snakes in either North or South America. The golden lancehead snake is extremely dangerous and the venom contracted from its bite could kill a human within an hour.
The golden lancehead snake has a population between 2,000 to 4,000 situated in the island’s rainforest, but there are many other varieties of snake on the island, with only a small amount of non-venomous snakes. There is estimated to now be between one and five snakes per square meter. For human protection and the welfare of the critically endangered golden lancehead snakes, Snake Island is completely off limits to the public.