What is it?

The British Indian Ocean Territory is one of the planet's last true blanks on the map — a scattering of 58 coral islands strung across the Chagos Archipelago, some 500 kilometres south of the Maldives, where the ocean is so clear that anchored yachts appear to float on glass. This is the site of the Great Chagos Bank, the largest atoll structure on Earth, and of a marine reserve covering roughly 640,000 square kilometres of some of the healthiest reefs left anywhere: manta rays cruising drop-offs, reef sharks patrolling in double figures, coconut crabs the size of dinner plates clattering through abandoned coconut plantations. The uninhabited atolls of Peros Banhos and Salomon feel post-human rather than pre-human — crumbling church walls, a village well, and gravestones swallowed by tournefortia scrub tell the story of the Chagossians, the islanders forcibly removed between 1965 and 1973 to make way for the US military base on Diego Garcia. It is a place of extraordinary beauty and genuine moral complexity, where the loudest sounds are noddies, fairy terns and surf on the reef crest. Nowhere else combines this level of ecological purity with such a raw, unresolved human history — and nowhere else in the Indian Ocean is so hard to legally set foot upon.

Where is it?

The territory lies in the central Indian Ocean, midway between Africa and Indonesia; Diego Garcia in the south hosts the joint UK–US military facility and is closed to visitors, while the northern atolls of Salomon and Peros Banhos are the only anchorages where permitted yachts may stop. Almost all visitors arrive by sailing yacht or expedition vessel from the Maldives, Sri Lanka, Seychelles or Thailand, a passage of roughly 4–10 days at sea. Aim for the inter-monsoon windows of March to May or October to November, when the trade winds ease, squalls diminish and visibility on the reefs can exceed 40 metres.

What makes it worth it?

Sailors who have anchored inside Salomon lagoon describe it in almost hushed terms — "the closest thing I've seen to the ocean before us," as one long-distance cruiser put it. You will snorkel over coral gardens with no other human within a hundred miles, watch the Milky Way rise unbroken by a single shore light, and walk a beach where your footprints are the only ones in living memory. But the memory that lingers is rarely the fish or the sunsets; it is standing in the roofless chapel on Île Boddam, reading a name on a headstone and understanding that paradise was someone's stolen home. Visitors leave with a rare double gift: awe at what the ocean can still be when left alone, and a sharpened conscience about who pays for wilderness. Years later you'll remember the silence — and the fact that you were one of only a few dozen civilians on Earth who saw it that year.

How accessible is it?

This is among the hardest destinations on the planet to reach legally — there are no tourist flights, no hotels, no ports of entry and no commercial tours. Diego Garcia is off-limits without military or contractor sponsorship; the only civilian access route is a BIOT Administration mooring permit for private yachts in transit, applied for well in advance through the Foreign, Commonwealth & Development Office, requiring proof of third-party insurance, a fixed itinerary and evidence you are self-sufficient in food, water and fuel (permit fees have historically run from around £100 to several hundred pounds, and conditions change without notice). Realistic costs therefore mean either owning a bluewater yacht or buying a berth on an ocean passage — expect roughly £3,000–£10,000+ per person for a multi-week crossing from the Maldives or Seychelles, plus provisioning. You need offshore sailing experience or at least sea legs, tolerance for days out of sight of land, and full self-rescue capability, as there is no medical facility, resupply or reliable communications beyond satellite. Note also that in 2024 the UK agreed in principle to transfer sovereignty of the archipelago to Mauritius while retaining Diego Garcia on a long lease, so access rules and permitting authorities may change significantly — always check the very latest guidance before committing. Fewer than a hundred civilians typically visit in a year, which is precisely why it belongs on a bucket list.