Mu Ko Ang Thong Marine Park

Ang Thong is an archipelago of roughly forty uninhabited limestone islands scattered across the Gulf west of Ko Samui, protected as a marine national park since 1980. Most visitors arrive on a day boat and get two set pieces. The first is Talay Nai on Ko Mae Ko, a saltwater lagoon trapped inside a collapsed karst and linked to the sea underground; a staircase climbs to a platform above it, and swimming is not allowed. The second is the viewpoint on Ko Wua Talap, a short but brutal scramble up chains and rock to a cleft that frames the whole scattered chain. The rest of the day goes on kayaking, a beach stop and snorkelling over patchy coral.

What you actually see

• Talay Nai lagoon - the trapped green saltwater pool seen from a stair platform.
• Ko Wua Talap viewpoint - a steep chain-assisted climb to the archipelago panorama.
• Kayaking between the karsts - flat water and sea caves along the cliff bases.
• Park headquarters beach - the only bungalows and campsite inside the park.

When to go

The park generally opens around February and closes in the monsoon months when landings become unsafe, though the dates shift year to year, so confirm before booking anything. Calmest water comes between March and May. Day boats leave Samui and Pha Ngan early and return late afternoon, and for most visitors that single day is the entire experience of the park.

Honest expectations

Day trips run like a conveyor belt: several boats hit the same two landings at the same hour, and the lagoon platform becomes a queue. The Wua Talap climb is steep, hot and unsuitable for anyone unsteady on rock. Coral at the snorkelling stops is average at best. Overnight park accommodation is basic and books out a long way ahead.

Nearby

Ko Samui and Ko Pha Ngan, both a couple of hours away by boat.