Ang Thong marine park
Forty-two islands, a lagoon you climb 500 steps to see, and the setting that inspired a novel about a hidden beach. From Samui it is ninety minutes, and it is the best day trip on the Gulf coast.
The climb
Koh Mae Ko has a saltwater lagoon in the middle of it, and a staircase of about 500 steps to the viewpoint above. It is steep, it is hot, and it is the photograph everyone comes for. Twenty minutes up for a fit adult, forty for most people, and there is a handrail the whole way.
The rest of the day is beaches and snorkelling — the park has some of the clearer water on the Gulf side, and the snorkel sites are shallow enough for children.
When it closes
The park closes roughly November to mid-December for monsoon. Outside that window crossings get rough and operators cancel without refunds. We check the marine forecast and will move the day rather than take you out in a swell.
| Time | Where | Note |
|---|---|---|
| 08:00 | Pickup | Bang Rak pier |
| 09:30 | Koh Wua Ta Lap | Beach and snorkel |
| 11:30 | Koh Mae Ko | The 500-step lagoon |
| 13:00 | Lunch | On the island |
| 15:30 | Return | Back on Samui by 17:00 |
Speedboat and crew, marine park fee, snorkel gear, life jackets, lunch, water. Not included: tips, kayak hire.
What the day is built around
Ang Thong is 42 islands an hour north-west of Samui, and the day has three fixed points: the Emerald Lake on Koh Mae Ko — a saltwater lagoon inside the island, reached by a staircase of about 200 steps — a kayak or snorkel stop on the north side, and the viewpoint climb at Wua Talap, which is 500 steps up a rope-and-root path and takes 50 minutes in heat.
The climb is optional and the boats wait, but it is the best view in the Gulf: the whole archipelago laid out in green and turquoise, with the mainland on the horizon. People who skip it spend the hour on a very good beach instead, so nobody loses.
The honest downside
It is a long day. Speedboat at 08:00, 45 minutes each way, three stops, back at the pier by 16:30. It is also the most popular trip on Samui, so the Emerald Lake has a queue at the stairs between 11:00 and 13:00 — we schedule it first or last depending on the day's boat allocation, and neither is empty in high season.
The park fee is ฿300 for adults and ฿150 for children, included in the $128 along with kayaks, snorkel gear, life jackets and lunch on the park's own restaurant pontoon.
When it does not run
The park closes to visitors for parts of October to December, when the Gulf monsoon makes the crossing unsafe, and the marine office can close it at 24 hours' notice for weather at any time of year. When that happens we cancel and refund in full rather than substitute a land tour — the alternative on Samui is not equivalent and we will not pretend it is.
Who it suits
Anyone who can climb 500 steps slowly. Children from about eight for the viewpoint, younger for the lake and the beach. Not suitable for pregnant travellers in a swell, and not for anyone who wants a quiet beach — this is the busiest day in the Gulf and it is still worth doing.
Before you book
How hard is the 500-step climb?
Steep but short, with handrails and shade at intervals. Not suitable for anyone with heart or knee problems — there is a beach at the bottom to wait on.
Is it good with children?
From about six, yes. The crossings are 90 minutes and can be bumpy; the snorkel sites are shallow.
When is the park closed?
Roughly November to mid-December, varying by year. We confirm before quoting.
Check your date.
Tell us the day and how many of you — we confirm availability, the boat and the price.
Written and checked by the Travel Thailand Tour team, Bangkok · Last updated · Prices are per person and were correct at the time of writing.