Destination guide
Ang Thong National Marine Park Guide
Forty-two limestone islands, an hour off Koh Samui
Ang Thong National Marine Park is an archipelago of 42 limestone islands about 30 km northwest of Koh Samui, and the best day trip you can take from Samui or Koh Phangan. Every tour is built around the same two stops. One is the Emerald Lake on Koh Mae Ko, a saltwater lagoon sealed inside a ring of cliffs. The other is the viewpoint on Koh Wua Ta Lap, a steep 500 m climb to the view of the whole archipelago.
Kayaking, a snorkel stop and lunch fill the rest of the day. There's no ferry, so you go on a tour, a big boat for about ฿1,200–1,400 or a speedboat for about ฿1,850–2,500. On top of that foreign adults pay a ฿300 park fee, often in cash on the day. The park closes every year from 1 November to 15 December, and February to April brings the calmest sea.
Arriving in Koh Samui
Where to stay in Koh Samui
This route ends in Koh Samui. Search Koh Samui hotels with your dates, or narrow it to the area you're heading for. Filter for free cancellation if you want to hold a room and decide later.
See Koh Samui hotelsOpens Booking.com with your dates · also on Expedia · Trip.com
Key Facts
Closed 1 November to 15 December
The park shuts for about six weeks every year in the Gulf's rainy season, when the sea is roughest. The exact dates can move with the weather, so check if your trip falls in late October or mid-December.
The park fee is ฿300
Foreign adults pay ฿300 and children aged 3 to 14 pay ฿150. Many tours leave it out of the price and collect it in cash at the park, so ask when you book and carry baht.
Tour boats only
No public ferry goes to the park, and only licensed operators may land. Speedboats take 45 to 60 minutes from Samui or Phangan. Big boats take about an hour and a half and leave from Nathon on Samui's west coast.
The viewpoint is a real climb
The trail on Koh Wua Ta Lap is only 500 m long but climbs steep rock steps with ropes to hold, 25 to 45 minutes up. Rest stops along the way have views too, and the one at 350 m is enough for most people.
The Emerald Lake is for looking
Stairs climb over the rim of Koh Mae Ko to a platform above the lagoon in 10 to 15 minutes. Swimming in it is banned, and so are drones across the park.
A full day, 07:00 to 17:00
Hotel pickups start around 07:00 to 08:00, and you're back on the island at about 16:00 to 17:00. The park itself is open from 08:00 to 17:00.
What You'll See in Ang Thong
The park covers 102 km² of sea, and most of its 42 islands are steep limestone hills under forest, with caves, small white beaches and lagoons inside them. Only Koh Wua Ta Lap, where the park headquarters is, and Koh Phaluai have anyone living on them. Alex Garland set the hidden lagoon of his novel The Beach in this archipelago, though the film was shot at Maya Bay on the other coast. Most of the day is spent cruising between the islands, and that alone is worth the trip. These are the places the boats stop.
The viewpoint on Koh Wua Ta Lap
The view from Pha Chan Charat, the viewpoint above the park headquarters, is the photograph that sells every tour, with islands stacked behind each other to the horizon. The trail is 500 m of rock steps and roots, steep enough that ropes run along much of it, with rest stops at 100, 200, 350, 450 and 500 m. Allow 25 to 45 minutes up. The first part is shaded, but the top isn't, and you'll usually be climbing around midday. Wear shoes with grip, because flip-flops make it harder, and take water. If you don't want the whole climb, the 350 m stop already gives you most of the view.
The Emerald Lake on Koh Mae Ko
Thale Nai, the "inner sea", is a saltwater lagoon in the middle of Koh Mae Ko, enclosed by cliffs and joined to the sea only by underwater tunnels. The boats tie up at a small beach, and a staircase climbs over the rim to a viewing platform above the green water, 10 to 15 minutes away on steep but shaded steps. It's the easier of the two climbs. Swimming in the lake is banned, so this stop is about the view, and most boats spend 20 to 30 minutes here.
The beaches, Bua Bok Cave and Koh Sam Sao
Koh Wua Ta Lap has the park's main beach, next to the headquarters, with toilets and a restaurant, and that's where most tours give you free time after lunch. Bua Bok Cave, also on Wua Ta Lap, has stalactites and stalagmites at the end of a short but rough scramble with ropes. Some guides take you there, others don't. Koh Sam Sao, beside Koh Mae Ko, has a stone arch over the sea and is a common kayaking stop.
Kayaking and snorkeling
Kayaking is the best way to get close to the cliffs and caves, and many speedboat tours include it. On big boats it's usually an extra. Snorkeling is the weak part of the day. Sediment from the Tapi River on the mainland clouds the water, and the reefs are modest, so think of it as a swim with some fish. Koh Tao and Koh Nang Yuan are much better for snorkeling.
Every Way to Ang Thong, Compared
| Trip | Leaves from | Time to the park | Cost | Best for |
|---|---|---|---|---|
| Big boat day tour | Nathon pier, Samui | About 1.5 hours | About ฿1,200–1,400, some from under ฿1,000 | A budget, a calmer ride if you get seasick, deck space |
| Speedboat day tour | Samui's north and northeast coast | 45–60 minutes | About ฿1,850–2,500 | More time in the park, smaller groups, kayaking included |
| Speedboat day tour | Thong Sala, Koh Phangan | About 45 minutes | About ฿1,700–2,500 | Staying on Phangan |
| Sailing or luxury boat | Samui | Longer than a big boat | From about ฿4,690 | Making the journey part of the day |
| Two- or three-day boat | Mae Haad, Koh Tao | About 3 hours | Ask the operator | Waking up in the park before the day boats |
| Every visitor | National park fee | Paid on arrival | ฿300 foreign adults, ฿150 children aged 3–14 | Often in cash, so ask if it's included |
Tour prices from the site's Koh Samui and Koh Phangan guides and the operators' listings. Most tours stop at the same two places, the viewpoint and the Emerald Lake, so what you're really choosing is the boat.
Big Boat or Speedboat?
I'd take the speedboat. It reaches the park in under an hour, so you get more time on the islands, groups are smaller, and kayaking is often in the price. Speedboats also pull up at the park's floating pontoons, while big-boat passengers often transfer by longtail. The drawback is the ride. When the wind picks up it's bumpy, the bow takes the worst of it, and the seats at the back are the place to be.
The big boat is the better choice on a tight budget, for children who'd rather move around a deck, or if you get seasick, because the slower, heavier ride is gentler on a calm day. It also carries up to 70 people, so you share the lagoon stairs with all of them, and it takes about an hour and a half each way, up to two on a rough day. The big boats all leave from Nathon on the west coast, so if you're staying in Chaweng or Lamai, add a drive across the island at both ends of the day.
Whichever boat you pick, check three things before you pay. Ask whether the ฿300 fee is included, whether the tour stops long enough on Wua Ta Lap for the full climb, and whether kayaking is part of the price or a rental on the beach.
How to Get to Ang Thong
Ang Thong is a tour-only park, and the tours start from Koh Samui and Koh Phangan. Hotel pickup is included in almost all of them. You can book through your hotel, at any of the travel desks in Chaweng, Lamai or Thong Sala, or online before you arrive.
From Koh Samui
Samui has the most departures. Pickups run from about 07:00 to 08:00. Big boats leave Nathon at around 08:00 to 08:30 and get back at about 16:30 to 17:00. Speedboats leave from the piers on the north and northeast coast, around Mae Nam, Bang Rak and Plai Laem, reach the park in 45 to 60 minutes and are back by about 16:30. Most tours run 8 to 9 hours door to door.
From Koh Phangan
Phangan's tours are speedboats from Thong Sala, some of them the Samui boats picking up on the way. Hotel pickup is usually between 07:30 and 08:30, the crossing takes about 45 minutes, and you're back by about 16:00, for about ฿1,700–2,500. Pickup covers most of the island but not the remote beaches, so expect a surcharge from Thong Nai Pan and no pickup at all from Bottle Beach. Don't book it for the morning after the Full Moon Party.
From Koh Tao
Koh Tao is about 55 km from the park, too far for the normal day tours. A few operators run two- and three-day boat trips from Mae Haad, about three hours each way, sleeping on board in the park, and they need a minimum group to sail. Otherwise, fit Ang Thong in when you pass through Phangan or Samui. If you're only on Koh Tao, its own snorkeling beats anything in Ang Thong.
What the Day Looks Like
The order changes from boat to boat, but the day follows a pattern. After the crossing, the first stop is usually a snorkel or a kayak along the cliffs, then Koh Mae Ko and the climb to the Emerald Lake. Lunch is a simple Thai buffet, served on board, at the headquarters on Wua Ta Lap or at the seafood restaurants on Koh Phaluai. The afternoon is Wua Ta Lap, with free time to climb to the viewpoint or stay on the beach, before the boat heads back in the mid-afternoon.
Two things make the day better. The first is the climb. The tours give you a fixed slot on Wua Ta Lap, and if you want the top of the viewpoint, start up as soon as you land rather than after a swim. The second is cash. Bring enough for the park fee, drinks and any kayak you rent on the beach.
Arriving in Koh Samui
Top-Ranked Hotels in Koh Samui
The top of my ranked list of the 10 best hotels in Koh Samui. Each button opens the hotel on Booking.com with your dates filled in.
#3Banyan Tree Samui4.8 (1,745 reviews)
Banyan Tree Samui cascades down a private headland bay south of Lamai — an all-pool-villa resort where every villa terrace holds its own infinity edge aimed at
Check rates
#4Conrad Koh Samui4.8 (1,698 reviews)
Conrad Koh Samui claims the island's southwestern corner — a hillside of contemporary pool villas built for one thing above all: the sunset.
Check rates
#5SALA Samui Choengmon Beach Resort4.8 (1,614 reviews)
SALA Samui Choengmon Beach Resort put pool villas within reach on Samui's calm northeast cove — the majority of its whitewashed, courtyard-style villas hide pri
Check rates
Is Ang Thong Worth It?
Yes, if you come for the scenery. The view from the top of Wua Ta Lap is among the best in the country, the Emerald Lake is unlike anything on Samui, and a day spent cruising between the islands is worth the price on its own. If you only do one boat day from Samui, make it this one.
Go with the right expectations, though. It isn't a secret, and at the lagoon stairs and on the viewpoint trail you'll be with a full boatload of people. It's a look-but-don't-touch park, with no swimming in the lagoon, cloudy water at the snorkel stops and only a few marked trails. The day is long and much of it is on the boat. If snorkeling is what you want, the Koh Tao and Koh Nang Yuan trip is the better day, and with children too young for the climbs, the half-day boat from Thong Krut to Pig Island and Koh Tan is the easier choice.
Staying Overnight in the Park
You can sleep in Ang Thong, and it's the only way to have the viewpoint to yourself before the day boats arrive. The park runs three bungalows near the headquarters on Koh Wua Ta Lap, two for two people at ฿600 a night and one for up to eight at ฿1,500, with a 30% discount from Monday to Thursday outside holidays. Camping costs ฿80 a person a night, and a tent for three can be rented for ฿450. The restaurant opens from 08:00 to 15:00 and from 18:00 to 20:00, and the electricity comes from a generator.
Bookings go through the Department of National Parks, whose online system was out of action for much of 2026, so you may need to call the visitor center on 061 285 7364, ideally with a Thai speaker. To get there, book a big-boat tour and arrange to come back on the next day's boat, which some operators allow at no extra charge. You pay the park fee once, on the day you arrive.
The Best Time to Visit Ang Thong, Month by Month
| Months | Rain on Koh Samui | What to expect |
|---|---|---|
| February to April | 64–116 mm, 4–6 rain days a month | The best months, with the calmest sea, the clearest water and the most reliable sun |
| May to September | 102–134 mm, 10–11 rain days | Good, with short showers and generally calm water while the Andaman coast has its monsoon |
| October | 295 mm, 16 rain days | Wet and often choppy, so book a flexible tour and keep a spare day |
| 1 November to 15 December | 445 mm in November, 16 rain days | Park closed |
| Late December to January | 263 mm in December, 127 mm in January | Open again, but the sea can still be rough, so keep a spare day |
Rainfall from the Koh Samui station's long-term averages. The Gulf's rainy season runs from October to December, months later than Phuket's.
What to Bring
Shoes or sports sandals with grip for the two climbs, swimwear, a hat, sunscreen and sunglasses, at least a liter of water for the viewpoint, and a dry bag for your phone if you're kayaking. Bring cash for the park fee and drinks, and seasickness tablets if you're on a speedboat on a windy day. Leave the drone at your hotel, because flying one in the park is banned.
Children are welcome and plenty go. The Emerald Lake stairs suit most ages, but I'd keep the full viewpoint climb for older children, since it's steep, rocky and hot in the middle of the day.
Plan the rest of your time on the Gulf islands.
Frequently Asked Questions
Common questions about Ang Thong National Marine Park Guide.
Yes, for the scenery. The viewpoint over the 42 islands and the Emerald Lake are the two best sights within reach of Koh Samui, and it's the best boat day from Samui or Koh Phangan. It isn't a snorkeling trip, though, because the water is often cloudy, and the main stops are busy.
It closes every year from 1 November to 15 December, in the Gulf islands' rainy season, when the sea is too rough for the tour boats and the park's reefs and beaches get a rest. The dates can shift a little with the weather.
฿300 for foreign adults and ฿150 for children aged 3 to 14. Many tours don't include it and collect it in cash at the park, so ask when you book.
On a day tour, since there's no public ferry. Big boats leave Nathon at about 08:00 to 08:30 and take about an hour and a half, for about ฿1,200–1,400. Speedboats leave the north and northeast coast and take 45 to 60 minutes, for about ฿1,850–2,500. Both include hotel pickup and lunch.
About 30 km northwest, which is 45 to 60 minutes by speedboat or about an hour and a half by big boat. Koh Phangan is about 35 km away, and Koh Tao about 55 km.
No. Thale Nai, the lagoon on Koh Mae Ko, is protected and swimming is banned. You see it from a platform above the water. You can swim from the beaches on Koh Mae Ko and Koh Wua Ta Lap.
Hard but short. It's 500 m of steep rock steps with ropes, 25 to 45 minutes up, and the top is in full sun. There are rest stops on the way, and the one at 350 m already has most of the view. Wear shoes with grip and take water.
Yes, on Koh Wua Ta Lap. The park has three bungalows, at ฿600 a night for two or ฿1,500 for up to eight, plus camping at ฿80 a person and tents to rent for ฿450. Book with the Department of National Parks, by phone if the website is down, and travel out and back on the big boats.
It's average. Sediment from the Tapi River often clouds the water and the reefs are modest. Koh Tao and Koh Nang Yuan are much better for snorkeling.
Not on a normal day trip, because it's about 55 km away. A few operators run two- and three-day boat trips from Mae Haad that sleep on board in the park. Otherwise, go from Koh Phangan or Koh Samui.
No, drones are banned across the park, including over the Emerald Lake.
Where to stay in Koh Samui
Compare prices across major booking sites, and filter for free-cancellation rooms if you want to reserve now and decide later.
- Compare prices across sites
- Filter for free cancellation
- Secure checkout on the partner site
Compare rates on Booking.com
Largest selection
Compare rates on Expedia
One Key member prices
Compare rates on Trip.com
Strong across Asia
We may earn a commission from bookings made through these links — at no extra cost to you. Learn more.
You Might Also Like
Bangkok City Guide
A city of three zones and a river — understand the layout and everything else falls into place.
Chiang Mai City Guide
A walled square, a mountain, and the best-value good living in Thailand — once you know the calendar.
Things to Do in Bangkok
Ten experiences worth the trip — ranked, priced, and timed so you catch each at its best hour.
Things to Do in Chiang Mai
Twenty-five things worth the trip north, ranked, priced, and timed around the mountain, the markets and the smoke-free months.
Best Time to Visit Thailand
November to February for most trips, and the right coast for the rest of the year
Written by
Mac Kiley
I lived in Bangkok for four years and traveled the country from there. The guides are my own opinions, written the way I'd explain them to a friend planning a trip.
More about MacReady to build your itinerary?
Use our free itinerary builder to save places, organize days, and share your trip.
Open Itinerary Builder