An Australian territory 2,600 kilometers northwest of Perth, where 63 million red crabs emerge each November to march from rainforest to sea in one of nature's most dramatic migrations. The spectacle transforms roads into rivers of crimson shells, with entire sections closed to traffic as crabs claim right of way to their spawning beaches.
Outside migration season, this 135-square-kilometer speck offers serious birdwatching — Abbott's booby nests only here and on one other island worldwide. Dense rainforest covers two-thirds of the land, hiding blowholes where Indian Ocean swells shoot skyward through coral limestone. The handful of beaches face powerful swells; swimming requires caution and local knowledge.
Access requires planning: two weekly flights from Perth, limited accommodation, and everything imported. Most visitors time their stay around crab season, though the island's isolation and endemic species reward patient naturalists year-round.