Off the coast of Brazil, there is an incredibly dangerous and tiny island that is out of bounds for a peculiar reason. Ilha da Queimada Grande lies off the coast of Brazil in the Atlantic Ocean and covers just 43 hectares (106 acres). 

It has become famous for its abundant snake population - one for every square metres - earning it the nickname of “Snake Island”. In fact, it is home to a species of viper so rare it is found nowhere else in the world. In part to protect this species, but also to protect humans from its fatal venom, tourists are completely banned, with only a select few permitted to dock.