Ilha da Queimada Grande, nicknamed Snake Island, is located off the coast of Brazil. It's home to a species of snake found nowhere else: the golden lancehead viper. There are approximately 2,000 to 4,000 vipers on the 430,000-square-meter island, and because their venom is so strong, the Brazilian Navy does not allow civilians to visit. There has never been an official report of a golden lancehead biting a human, but examinations of the snake's hemotoxic venom deem it extremely potent. Other species of lanceheads have caused more deaths than any other type of snake in North and South America.