British Indian Ocean Territory

A vast, shallow lagoon enclosed by the curving spine of Diego Garcia, the largest and southernmost atoll of the Chagos Archipelago, famous for its extraordinary coral reef biodiversity and its contested role as a US military base.

A compact group of seven small islands crowning a single reef platform at the northern edge of the Chagos Archipelago, notable for their near-pristine reefs, significant seabird nesting colonies and the sudden depth drop that surrounds the platform, creating dramatic marine conditions.

The largest submerged atoll in the world, covering an area of about 12,642 square kilometres in the northern Chagos Archipelago, almost entirely uninhabited and hosting some of the most extensive healthy coral reefs remaining in the Indian Ocean.

A small, flat coral island in the southern Chagos Archipelago, historically one of the last Chagossian communities before the population was removed, now uninhabited and reverting to a coconut-and-bird landscape of quiet ecological and historical significance.

The second-largest atoll in the Chagos Archipelago, centred roughly 500 kilometres south of the Maldives, uninhabited today but historically significant for its salt production and Franco-Mauritian fishing communities of the 18th and 19th centuries.

A rare double atoll in the Chagos Archipelago, composed of two separate land areas connected by a sandy isthmus that floods at high spring tides, situated approximately 50 kilometres southwest of Peros Banhos.