Geography of the British Indian Ocean Territory

It measures 60 square kilometres (23 sq mi) and accounts for almost three-quarters of the total land area of the territory.

[1][disputed – discuss] Diego Garcia is the only inhabited island and is home to the joint UK-US naval support facility.

The bed slope noted at the outer edge of the reef shelf is steep towards the deeper end; the depth drops to more than 450 metres (1,480 ft) in some areas within 1 kilometre (0.62 mi) distance from the shore.

Diego Garcia lies at the southernmost tip of the Chagos-Laccadive Ridge — a vast submarine range in the Indian Ocean.

Lying between Diego Garcia in the south, and the Peros Banhos and Salomon Atolls in the north, the remaining coralline islands are scattered over a wide area of the Great Chagos Bank, an area of atolls, reefs and shoals with an average depth of water of some 20 metres.

A hundred km to the southwest of Nelson are the 3 islands of Trois Frères, which were briefly inhabited in the 19th century.

Finally, Six Îles Atoll (also called Egmont), 5 leagues (24 km) further south of Danger, was also occupied for short periods during the mid 19th century[19] until 1935.

The atoll, in the form of "U", is a small strip of land with width varying from 30 metres (98 ft) to a maximum of 3 kilometres (1.9 mi) at its northern extremity.

[17] In the late 18th century, coconut palm plantations were established on the island to produce copra for which slave labourers were brought in from Africa.

[3][5] A small population lived in the archipelago, descendants of Mauritian laborers working the copra industry.

[21] After an agreement was signed in 1966 between Britain and the United States, the US built a military base and forcibly evacuated all indigenous people; 1,200 from Diego Garcia, Ile du Coin, and Île Boddam were relocated to Mauritius,[22] while others went to the Seychelles.

Further complications arose after the 2010 establishment of the world's largest marine reserve as the islanders' commercial fishing capabilities, if they returned to the archipelago, would be curtailed, thus hampering their traditional livelihood.