Ang Thong National Park: The Day Trip from Koh Samui

Among the day trips from Koh Samui, one is right near the top: Ang Thong National Park. Forty-two limestone islands, dense jungle running down to the water, a turquoise-green lagoon inside one of the islands, and a viewpoint from which you can take in the whole archipelago. Here's what to expect, how to get there, and what to check before you book.

What is Ang Thong National Park?

Its official name is Mu Ko Ang Thong, which translates roughly as "archipelago of the golden bowl" — which is why tours often call it the "Golden Basin". The marine national park lies around 30 kilometres northwest of Koh Samui in the Gulf of Thailand and has been protected since November 1980. It covers about 102 km², of which only around 18 km² is land — the rest is sea.

There are no hotels or beach bars here, only the park headquarters on Koh Wua Talap with a handful of simple lodgings. That's exactly the appeal: you get a slice of Thailand that looks like the postcards, without anyone having set up a sunbed next to it.

Is it worth visiting?

For most people: yes. If you enjoy scenery, views and a day out on the water, this is one of the most striking excursions in the whole region. To be fair, though, it's worth being clear about what the park isn't:

• Not a top snorkelling spot. The water is shallow and often clouded by sediment. If fish and coral are your priority, a trip to Koh Tao and Koh Nang Yuan is a better bet.
• Not a swimming paradise at the lagoon. You see the famous emerald lagoon from above — swimming there is banned.
• A long day. Pick-up in the morning, return in the late afternoon — worth factoring in if you're travelling with children or prone to seasickness.

Once you know that, you won't be disappointed. Many of the negative reviews online come down to exactly this: people expected a snorkelling paradise.

The highlights of a tour

The emerald lagoon on Koh Mae Koh

On the island of Koh Mae Koh lies the Emerald Lake, known in Thai as Thale Nai: a saltwater lake inside the island, connected to the sea underground, that shimmers anywhere from green to turquoise depending on the light. A wooden walkway with steps leads up to a platform where you look down over it. Swimming is strictly forbidden, as the lake is under special protection.

The viewpoint on Koh Wua Talap

For many visitors, the real highlight is the viewpoint on Koh Wua Talap, the island with the park headquarters. The climb takes around 30 minutes and is steep and partly rocky — hard going in flip-flops. From the top, the whole archipelago spreads out below you, and on a clear day you can see as far as Koh Samui and Koh Phangan. If you'd rather skip the climb, you can simply stay on the beach below.

Kayaking, a cave and a beach

Depending on the tour, you can paddle a kayak along the rocky coastline, visit a small stalactite cave, and swim and snorkel from one of the white sand beaches. Whether kayaking is included in the price or costs extra varies from tour to tour — check the tour description before you book.

Can you snorkel in Ang Thong National Park?

Yes — at the swim stops on the tours, and good operators provide the equipment. Expect more of a pleasant swim among a few fish than a picture-book coral reef, though. Only the emerald lagoon itself is strictly off-limits for swimming.

How do you get to Ang Thong National Park?

By boat only — there's no bridge or scheduled ferry. Practically every visitor arrives on an organised day tour from Koh Samui or Koh Phangan. Tours pick you up at your hotel in the morning and bring you back in the evening.

You'll usually be choosing between two types of boat:

• Speedboat: faster around the park, so more stops in a single day. You'll feel the swell more, though.
• Big boat: calmer, with plenty of deck space, and lunch is usually served on board. The crossing takes longer, but you get more time at each stop.

On kohsamui.tours you'll find both options with hotel pick-up, lunch and snorkelling gear included. The itinerary, departure pier and current prices are listed on each tour page:

from 1,850 THBAngthong Marine Park Full-Day Speed Boat VIP Tour★★★★★4.72 from 389 reviews from 1,250 THBAngthong Marine Park Full-Day Big Boat Economy Tour★★★★★4.76 from 361 reviews

What does entry cost?

For foreign visitors, the national park costs 300 baht per adult and 150 baht per child. Note that on many tours — including both above — this park fee is not included in the tour price and is payable separately. Ask when booking how and when it's collected, and bring some cash.

When is the park closed — and when's the best time to go?

Ang Thong National Park closes every year for a few weeks, because the sea on the Gulf side tends to be rough during that period and the park gets a break. In 2026 the park is closed from 1 November to 15 December — as announced by the national park authority. No tours run to the park during this period, and overnight stays aren't possible either.

The authority also closes the park at short notice on individual days when wind and waves are too strong — most recently on 8 and 9 January 2026. If you're travelling around the closure period or in uncertain weather, ask when booking whether the tour is going ahead.

Outside the autumn rainy season, the sea is usually noticeably calmer. For more on the weather through the year, see our article on Koh Samui weather and the truth about the rainy season and our overview of the best time to visit Koh Samui.

What should you bring?

• Sturdy shoes or grippy sandals for the climb to the viewpoint
• Sun protection, a hat and plenty of water — there's no shade at the top of the viewpoint
• Cash for the park entrance fee
• A waterproof pouch for your phone and camera if you're kayaking
• If you're prone to seasickness: take tablets before departure, not once you're on board

Frequently asked questions

How long does a trip to Ang Thong National Park take?

Plan for a full day: pick-up in the morning, back at your hotel in the late afternoon. Exact times are listed on each tour page.

Is the trip suitable for children?

Yes, for children who can manage a long day on a boat. The walk to the lagoon is short, while the climb to the viewpoint is tough going for small children — though it can be skipped. Children pay the reduced park entrance fee.

Can I stay overnight in the park?

Yes, the national park authority rents out simple bungalows and tents on Koh Wua Talap. For most visitors, though, the day tour is the easier choice.

Which is better: Ang Thong or Koh Tao?

It depends what you're after. Ang Thong wins on scenery, the lagoon and the view. Koh Tao and Koh Nang Yuan are the better choice if snorkelling comes first. If you like both and have the time, do both trips.

For more ideas for your days on the island, see our Top 10 activities on Koh Samui. And if you want a preview first, our post Angthong Marine Park on video shows the park from above.