Snake Island, also known as Ilha da Queimada Grande, is a small 43 hectare island off the coast of Brazil that is home to an abundant population of golden lancehead pit vipers, which are the island's only natural inhabitants. The snakes became isolated on the island thousands of years ago when rising sea levels separated it from the mainland, allowing the snakes to evolve adaptations to the new environment and proliferate to such large numbers that the island is now too dangerous for public access.