Côn Đảo: Prison Islands Turned Eco-Sanctuary

Côn Đảo is an archipelago of 16 islands 230 km off the southern coast of Vietnam, administratively part of Bà Rịa-Vũng Tàu province. Until 1975 the main island, Côn Sơn, was a prison — French colonial from the 1860s, then American-backed South Vietnamese until reunification. Today it's the country's most remote and least developed tourist destination, with the cleanest beaches in Vietnam, year-round sea turtle nesting, and a single international-luxury resort.

What's distinctive

The prison history

Phú Hải Prison and the "Tiger Cages" at Trại Phú Tường are preserved as museums. The Tiger Cages are particularly disturbing — small open-roofed concrete cells where political prisoners (Communist Party members) were held in conditions that came close to torture by exposure. Lime was poured down on cell occupants by guards from above.

The cemetery at Hàng Dương holds many of those who died here, including the revolutionary heroine Võ Thị Sáu — executed by firing squad in 1952 at age 19. Her grave is a continual pilgrimage site, with offerings of sweets, cosmetics and lipstick.

This is the most important war-and-prison memorial in southern Vietnam outside Ho Chi Minh City. Two or three hours covers the essential sites.

The beaches

• Bãi Đầm Trầu: the famous one — white sand, calm water, sea turtle nesting in season.
• Bãi Lò Vôi: closer to town, easy swimming.
• Bãi Nhát: rocky and atmospheric.
• Bãi Ông Đụng: hike from the road to reach.

Visibility for snorkelling and diving is the best in Vietnam — Côn Đảo Marine National Park protects much of the surrounding reef.

Sea turtle nesting (May–October)

Green sea turtles nest on multiple beaches across the archipelago. The park runs a small turtle-conservation programme; visitors can join overnight monitoring trips with rangers on Hòn Bảy Cạnh island. Book through the park or your accommodation.

Diving

10–20 m visibility, healthy coral, occasional dugong sightings. Several dive shops operate (Côn Đảo Dive Center, others). Dives typically combine reef and wreck.

How to get there

The flight is the standard. The airport on Côn Sơn island is small and right on the coast — the approach is one of the more dramatic in Vietnam.

When to visit

• March–September: dry season, calm seas, best diving. Turtle nesting peaks June–August.
• October–February: wet season — rougher seas, ferry suspensions, some dive operators close.

Where to stay

• Six Senses Côn Đảo: the famous luxury option. From $700/night. Beachfront villas, the only true international-luxury resort on the island.
• Côn Đảo Resort: mid-range, in town.
• Saigon Côn Đảo Resort: state-run, mid-range.
• Several small guesthouses and homestays in Côn Sơn town for budget.

Inventory is limited; book ahead, especially around Vietnamese long weekends.

Practicalities

• Cash: ATMs limited. Bring sufficient VND from HCMC.
• Motorbike rental is the standard local transport. ~150k VND/day.
• Marine park entry: small fee at the gate of National Park areas.
• Phone signal: good in Côn Sơn town, patchy elsewhere.

What it isn't

Côn Đảo is not a backpacker party island. It's not Bali or Phú Quốc. The atmosphere is reverent (because of the prison history), the beaches are beautiful but not lined with bars, and most visitors are Vietnamese pilgrims, Six Senses guests, or divers. That's what makes it special.

Who should come

• Anyone wanting Vietnam's cleanest beaches without the crowds
• Divers and snorkellers
• People interested in Vietnam War / colonial-prison history
• Travellers willing to pay more (flights and accommodation are pricier than mainland Vietnam)

Skip if you want lively nightlife, easy logistics, or a beach destination you can stretch a backpacker budget at.

Quick verdict

Côn Đảo is Vietnam's remotest island archipelago — a former colonial and wartime prison transformed into a marine sanctuary. It's most loved for its pristine coral reefs, year-round sea turtle nesting, and the clearest diving visibility in the country. It's not a backpacker party island, nor a budget beach destination; most visitors are either pilgrims paying respects to revolutionary history, luxury resort guests, or serious divers.

Best for / not ideal for

Best for:

• Divers and snorkellers seeking Vietnam's best reef and wreck visibility (10–20 m)
• Travellers interested in war and colonial-prison history who can spend 2–3 hours at memorials
• Couples or solo travellers wanting peaceful, uncrowded beaches far from the tourist infrastructure of Phú Quốc or Hạ LongHạ Long (Ha Long)hah longBay in northeastern Vietnam featuring thousands of limestone karst islands; a UNESCO World Heritage site and top cruise destination.

Not ideal for:

• Budget backpackers (flights and accommodation are 2–3× more expensive than mainland Vietnam)
• Visitors seeking lively nightlife or beach bars; most venues close early

How long to stay

Most visitors stay 2–3 nights — enough for a half-day prison history tour, a beach day, and a reef dive or snorkelling trip. Four nights allows a day trip to Hòn Bảy Cạnh for sea turtle monitoring (May–October), or multiple dive trips. Less than 2 nights means skipping either the historical sites or a water activity, neither ideal given why people come.

Climate by month

Best months are March–September, the dry season with calm seas and maximum visibility for diving (10–20 m consistently). Turtle nesting peaks June–August. October–February is wet season; seas roughen, ferries suspend frequently, and some dive operators close. Rain itself is rarely all-day, but it makes road transport slower. See /practical/weather-by-month for full seasonal detail.

Day trips from here

• Hòn Bảy Cạnh island (overnight ranger patrol): guided sea turtle monitoring and nesting sites; book via Côn Đảo Marine National Park (May–October).
• Dive or snorkel the archipelago reefs: Côn Đảo Dive Center runs reef and wreck trips.
• Gull Island (Hòn Dau): accessible by small boat; bird-watching and rocky scenery.

Local transport

Most visitors rent a motorbike (~150k VND/day) to reach the four main beaches and prison memorials. Walking around Côn Sơn town is safe and pleasant. Grab does not operate widely on the island; cash-paid moto-taxis are the fallback in town. Ferry access to the outer islands (Hòn Bảy Cạnh, etc.) is arranged through your accommodation or the marine park office.