Answer: Brazil

Off the coast of Brazil is a beautiful island known known formally as Ilha da Queimada Grande. The formal name, roughly “the big burnt island”, is derived from practices carried out by old fisherman who tried to burn back the jungle from the shore to create a place to carve out a fishing village. The informal name of the island, however, tells the real story of the place: Snake Island.

Ilha da Queimada Grande is, outside of the winter nests some northern garter snakes temporarily congregate in, the most snake dense region in the world. The average density of snakes on the island is roughly three per square meter. Mark off a space the size of your average office, around 10 square meters, and you’ll be sharing your workspace with around thirty snakes.

Not just any snakes, mind you, Ilha da Queimada Grande is the sole home of one of the world’s deadliest snakes: the Golden Lancehead pitviper. Despite occupying the top of the food chain on the island and being completely devoid of any natural predators, however, the Lanceheads are critically endangered. A combination of over/inbreeding, the small size of the island, and the way the geography of the island fragments the populations of Lanceheads further exacerbates the problem of genetic diversity.

Other than a small area of the island maintained by the Brazilian Navy for a lighthouse, the island (as you can imagine) remains uninhabited.