Ang Thong National Marine Park
Forty-two limestone islands with hidden lagoons, a viewpoint over the whole archipelago and the Emerald Lake.
Ang Thong National Marine Park is 42 islands 30km west of Koh Samui, best known for the Emerald Lake on Koh Mae Ko and the viewpoint on Koh Wua Talap. A full-day speedboat trip costs from 1,800 baht.
Open Ang Thong National Marine Park in Google Maps9.6250, 99.6667
Tour price excludes the THB 300 marine park fee at the pier
Entry fee checked against operator or park publication, October 2026. Hours can change without notice — confirm on the day.
Forty-two limestone islands with hidden lagoons, a viewpoint over the whole archipelago and the Emerald Lake.
The park's 102km² of limestone islands were the setting for Alex Garland's novel The Beach, and the Emerald Lake — a saltwater lagoon enclosed by cliffs — is the image on the book's cover. The islands have no permanent residents beyond a small ranger station, and the interior is dry evergreen forest and mangrove.
It is the best day trip from Samui and the landscape is different from the Andaman — inland lagoons rather than open bays. The viewpoint climb is short and spectacular.
What you’ll actually see
- The Emerald Lake (Thale Nai) on Koh Mae Ko, reached by a 10-minute stair climb
- The Koh Wua Talap viewpoint, a steep 40-minute climb to a 500-metre panorama
- The sea kayaking channels between the northern islands
- The white sandbar at Koh Sam Sao, exposed at low tide
How to visit it well
- Speedboat from Samui takes 45 minutes; slow boats take 2 hours.
- The viewpoint climb is 500 steps — start early before the heat.
- Kayaking around the islands is included in most good tours.
Mistakes worth avoiding
- Booking the cheapest speedboat, which visits three islands in five hours and rushes all of them
- Skipping the Wua Talap viewpoint because of the climb — it is the whole point
- Not bringing reef-safe sunscreen; the park bans chemical sunscreens in some zones
Is it worth it?
The best day trip from Samui and worth the money. It is a long day — 90 minutes each way by speedboat — but the lagoon and the viewpoint are genuinely exceptional. Book a boat that allows two hours on Wua Talap.
Common questions
From 1,800 baht per person on a shared speedboat with lunch, snorkelling and transfers. Private charters start around 12,000 baht for the boat.
About 90 minutes by speedboat each way, 2.5 hours by slower boat. The day runs from 8am to 5pm.
It is steep and hot — 40 minutes up with ropes on the last section. Anyone reasonably fit can do it; it is not suitable for young children or bad knees.
The park closes to visitors from 1 November to 15 December each year for monsoon recovery. Check dates before booking.
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Last updated: October 2026 · Prices and hours checked by Nattapong Srisuwan