See inside Diego Garcia, a secretive US Navy base on British land at the center of a bitter tug-of-war in the Indian Ocean

Diego Garcia is surrounded by about 60 other atolls.

Its coast forms a deep natural harbor, making it the perfect site for a naval base.

It is home to turtles, giant migrating birds and the coconut crab – the largest land-based animal on the island.

There are also civilian contractors, mostly from nearby Mauritius, who cook and clean for the soldiers and sailors.

In their downtime, US military service personnel can spend their time bowling, cycling, or shopping.

From Diego Garcia, US bombers launched attacks in Afghanistan in the wake of the 9/11 attacks, and on Iraq during the 2003 invasion of the country by the US and its allies.

Prior to that, the site had proved its strategic importance for US military operations in the Middle East as a base for Air Force attacks during the first Gulf War in 1991.

From the base, long-range B52 bombers embarked on missions to Afghanistan in 2001, targetting Taliban and al-Qaeda positions in the country's mountains.

Its deep port is able to accommodate aircraft carriers, nuclear submarines, and other ships.

"There are also massive pre-positioned ships in the lagoon, each about the size of the Empire State Building, filled with enough weapons and supplies for material tanks, helicopters for an entire brigade of Marines," David Vine, who has written a book on the Chagos islands, told CNN.

Unlike the US military base in Guam, the spouses of personnel are not allowed on Diego Garcia. No journalist has visited.

Lawrence Wilkerson, a former official in the Bush administration, told Vice News in 2015 that CIA contacts had informed him it served as one of the network of prisons where people were detained, interrogated and in some cases tortured as part of the War on Terror after 9/11.

The claims have been awkward for the British. Officials in the UK government have long denied UK complicity or involvement in the so-called "extraordinary rendition" program.

The ancestors of the Ilois had been transported to the islands as slaves to work coconut plantations in the 18th century.

But after being forcefully uprooted in the 1960s and 1970s, most of the Chagossians were moved to nearby Mauritius or the Seychelles, where they faced poverty and discrimination.

Some moved then to Britain, where they have continued to experience hardship.

The Ilois have fought for the right to return to their homeland, with the British High Court in 2006 ruling that their expulsion was illegal.

The British government has continued to deny that it broke laws in expelling the Ilois, and has blocked their right to return.

In May 2019, the UN's highest court ruled that the 60 or so Chagos Islands — which include Diego Garcia — had been transferred to British authority illegally in 1965.

The islands were previously part of Mauritius, but Mauritius handed control of them to Britain for a cash fee two years before gaining independence.

The UN court ruled that it was illegal for the British to demand possession of the islands as a condition of independence.

Shortly afterwards, the British leased Diego Garcia to the US.

The UN has now served an eviction notice to the British. Although the ruling is not enforceable, it exerts moral pressure, and has placed the future of the base in doubt.