Christmas Island is nature's surprise package—lush rainforest draped over limestone cliffs, reefs alive with corals, and an annual migration of millions of red crabs that turns the forest floor into a moving carpet. Underwater, whale sharks arrive in sync with spawning events, while manta rays and tropical fish swim over untouched coral gardens. With its endemic birds, bats, and marine life, the island is an ark of biodiversity in the heart of the Indian Ocean.