The plane is a small turboprop and it takes forty-five minutes from Ho Chi Minh City. When the island appears below you it looks improbable — forested mountains rising out of the sea with a ring of white sand beaches at their base, the water in gradients of green and blue — and the descent is steep enough that you’re suddenly at tree level before the wheels touch. Côn Đảo is 230 kilometers off the southern coast, about as remote as you can get within Vietnam’s domestic network, and this is most of what protects it.
The French built a prison here in 1861. The Americans maintained and expanded it. The Tiger Cages — concrete cells barely larger than a wardrobe, open to the sky, where political prisoners were kept in isolation under conditions that make the word “brutal” seem inadequate — were not exposed to the world until a US Congressional delegation accidentally found them in 1970 and published photographs that became one of the enduring images of the war. I spent two hours in the prison complex, which is now a museum, and came out needing to walk for a while in silence before I could speak to anyone.
The island holds both things in tension: the history, which is heavy and unavoidable, and the natural world, which is extraordinary and seemingly indifferent. The surrounding national park protects a reef system and several nesting beaches for green sea turtles. I rented a motorbike and drove at dusk to a beach on the south coast where the park rangers told me turtles sometimes come ashore. I sat in the dark for two hours and watched a female, easily a meter across, haul herself out of the surf, dig a nest with her back flippers, lay over a hundred eggs, cover them methodically, and drag herself back to the ocean. The whole process took an hour and a half. She didn’t acknowledge me at any point.
The main town of Côn Sơn has a colonial French grid of roads, a few villas behind high walls, a beautiful cemetery where Vietnamese revolutionaries are buried under the shade of old trees, and a seafront of exceptional quiet. The restaurants are few and simple and serve fish caught that morning. There is almost no nightlife, no club scene, no organized entertainment of any kind. The island generates its own pace, which is slow and serious and surprisingly restorative.
The reef diving is among the best in southern Vietnam — visibility often exceeds fifteen meters, and the fish populations are dense enough that you can spend an hour on a single coral head without covering much distance.
When to go: May to September for sea turtle nesting season — this is when the beach watches happen, though you’ll need to coordinate with the national park rangers. The diving is best November through April when visibility peaks. Avoid October, when storms can ground flights for days.