- Ang Thong is a national marine park of 42 limestone islands about 28 km west of Koh Samui, with no public ferry, so visits are by organised tour or private boat.
- The park entrance fee is ฿300 per adult and ฿150 per child, paid in cash unless your tour already includes it.
- The park is usually closed every year from 1 November to 15 December to let nature recover, and no tours run in that window.
- A typical day covers four to six stops out of the 42 islands: snorkeling, the Emerald Lake on Mae Ko, the Wua Ta Lap viewpoint and a beach lunch.
- Tours are run by licensed local boat operators and sold through agencies such as ours; nobody "owns" the park, it is managed by Thailand's national park authorities.
Stand on the deck as the boat clears the last pier buoy and Koh Samui shrinks behind you, and the question answers itself: ahead is a scatter of green, cliff-sided islands that look nothing like the beach resorts you just left. That is Ang Thong National Marine Park, and most people who ask what it is have only seen one photo of a lake inside an island and want to know if the rest is real.
It is real, and it is also a working national park with rules, a fee, and a closed season, not a theme park you can turn up to whenever you like. This guide covers the basics plainly: where it is, what the islands are like, what a day visit includes, who looks after the place, and how to pick a tour once you understand what you are choosing between.
What is Ang Thong National Marine Park, exactly?
Mu Ko Ang Thong National Marine Park is a protected group of 42 limestone islands in the Gulf of Thailand, about 28 km west of Koh Samui. The name means "bowl of gold", and the islands cover roughly 102 square kilometres of sea, cliffs, hidden lagoons, coral reefs and a bit of mangrove.
It has been a national park since 1980, which in practice means the Department of National Parks sets the rules: an entrance fee, a protected coral reef, a closed season, and limits on where boats can anchor. Only two of the 42 islands have any people living on them at all, which is part of why the place still looks untouched.
Where is it, and how do you actually get there?
There is no public ferry to Ang Thong. The only ways in are an organised day tour, a sailing cruise, or a private boat charter, all of which leave from piers on Koh Samui.
Depending on the boat, the crossing takes anywhere from about 40 minutes by speedboat to around an hour and a half on a large tourist boat. That difference matters more than people expect, because every extra hour at sea is an hour not spent on an island. We cover the piers, crossing times and transfer details properly on the how to get there page if you want the full comparison.
What do the islands actually look like?
Picture sheer grey-green limestone walls dropping into turquoise water, topped with thick forest, with the odd white sand beach wedged between the cliffs. A few islands hide something stranger inside: Koh Mae Ko has a saltwater lake sealed inside its rock walls, and Koh Sam Sao has a natural stone arch you can kayak under.
You will not visit all 42 in a day, nobody does. A normal tour stops at four to six of them, chosen because they have a beach, a viewpoint, or good snorkeling, while the rest stay as green shapes on the horizon that you pass on the way.
The islands you are most likely to stand on
- Koh Mae Ko: home to the Emerald Lake, a green saltwater lagoon you view from a stairway above it. Read more on the Emerald Lake page.
- Koh Wua Ta Lap: the park headquarters, with a steep viewpoint trail, a langur-filled beach and a lotus-stalactite cave. Full detail on the Koh Wua Ta Lap page.
- Koh Wao: shallow reef, the usual snorkeling stop on the speedboat and VIP tours.
- Koh Sam Sao: the rock arch and the best kayaking water in the park.
- Koh Phaluai: the largest island, with the only fishing village in the park.
What does a day visit actually include?
A standard day trip means hotel pickup before 8am, a boat crossing, four or so stops with snorkeling, a steep walk or two, a beach lunch, and a return to your hotel by late afternoon or early evening. It is a full day, not a half-day add-on.
Every tour we sell follows roughly that shape, with different pacing, group size and inclusions. Here is the pattern of a typical speedboat day, just to put the shape of it in front of you:
| Time | What happens |
|---|---|
| 07:40 | Hotel pickup on Koh Samui |
| 09:00 | Crossing to the park, about 40 minutes by speedboat |
| 10:00 | Snorkeling on a coral reef |
| 11:00 | Stairway up to the Emerald Lake on Mae Ko |
| 12:00 | Buffet lunch and kayaking on the beach |
| 14:00 | Viewpoint climb or beach time on Wua Ta Lap |
| 16:30 | Back on Koh Samui, drop-off at your hotel |
Two things people underestimate: the heat, and the stairs. Both viewpoint climbs are steep, the Mae Ko one short and the Wua Ta Lap one longer and harder, and the sun in the middle of the day is strong with very little shade on the trails. Bring water, a hat and shoes with grip, not flip-flops.
Who runs the park, and why is it protected?
The park itself is managed by Thailand's national parks authority, which sets the entrance fee, the closed season and the conservation rules. The boats you see are run by licensed local operators, and we are a licensed travel agency (TAT 44/00444) that books you onto their tours and looks after the booking, not the boat owner.
The protection is not just paperwork. The coral reefs are slow-growing and easily damaged by standing on them, the Emerald Lake is closed to swimming to keep its ecosystem stable, and the whole park closes for six weeks a year to give the islands a break from boat traffic during the roughest part of the monsoon.
The park is closed every year from 1 November to 15 December, and no tours run at all in that window, regardless of which operator you book with. If your trip falls near those dates, check before you plan anything else around a park visit.
What does it cost to visit, and what is the entrance fee?
The national park entrance fee is ฿300 per adult and ฿150 per child, paid in cash at the park unless your tour already has it built into the price. That fee is separate from the tour price itself, which covers the boat, guide, lunch and transfers.
Some tours fold the park fee into the headline price, which is worth knowing before you compare numbers:
- Speedboat and big boat tours: park fee not included, pay ฿300/฿150 in cash on the day.
- VIP speedboat and Red Baron cruise: park fee included in the ticket price.
- Private charter: park fee not included, same ฿300/฿150 rate, though children 12 and up pay the adult rate.
Which tour should you actually book?
This is really a question about pace, budget and group size, not about which tour is "best". If you want the most islands in one day at a fair price, the fast crossing and four stops on the speedboat tour suit most first-time visitors. If you would rather pay once and not think about cash for the park gate, want a smaller boat, and like the idea of six stops instead of four, the VIP speedboat tour is worth the jump in price.
If you get seasick easily, travel with young children, or just want the cheapest full day out, the big boat tour is slower to get there but far smoother on the water and easier on the budget. For something more relaxed and scenic, with meals served on deck under genuine red sails, look at the Red Baron sailing cruise, and if you want nobody else's schedule but your own, the private speedboat charter lets you set the route and the pace yourself.
None of these are wrong choices. They are different trips wearing the same destination: fast and full versus slow and included versus private and flexible.
What should you leave at the hotel?
Keep it simple and practical rather than packing for a resort day. A dry bag or waterproof phone pouch does more for you than anything else on this list.
- Swimwear, worn under your clothes to save time
- A hat, sunglasses and proper sunscreen, reapplied at lunch
- Shoes with grip for both viewpoint climbs
- Cash for the park fee if your tour does not include it
- A photo of your passport for the tour's insurance paperwork
Booking basics worth knowing before you commit
A booking request on our site costs nothing and takes no payment up front. A manager confirms your date by WhatsApp or email and sends a payment link for a prepayment, usually half the total, with the rest settled on the day of the tour.
Plans change, so it is worth reading the cancellation policy and terms and conditions before you pay anything, particularly the cut-off for a refund if you cancel versus if the tour operator cancels for weather. Weather calls on the day are made by the captain, not by us or by you, and that is for genuine safety reasons on open water around limestone cliffs.
If you are still deciding which stops matter most to you, the full Ang Thong park guide breaks down each island, the wildlife you might see, and a month-by-month read on sea conditions, which is a useful next stop before you book.
Questions and answers
Is Ang Thong worth visiting if I only have one day on Koh Samui?
Yes, a single day is enough to see the Emerald Lake, climb a viewpoint, snorkel and have lunch on a beach, which is exactly what the standard tours are built around. You will not see all 42 islands, but nobody does in one visit.
Can I visit Ang Thong without booking a tour?
No, there is no public ferry and no way to reach the park independently, so a tour, sailing cruise or private charter from Koh Samui is the only option. All of them include hotel pickup.
Is the park fee always extra on top of the tour price?
Not always. The speedboat, big boat and private charter prices do not include the ฿300 adult or ฿150 child park fee, while the VIP speedboat and Red Baron cruise already have it built in.
What happens if my trip falls during the annual closure?
The park is shut every year from 1 November to 15 December and nobody can book a tour during that window, no matter which operator you ask. If your dates are close to either end, check with us before planning the rest of your trip around it.
Is Ang Thong suitable for people who get seasick?
The big boat tour is the smoothest option since it is a large, stable vessel, while speedboats feel the swell more on a rough day. If you are prone to seasickness, mention it when booking and take medication in advance rather than on the boat.
Are children allowed on Ang Thong tours?
Yes, most tours have set child prices and age brackets, and kayaking in the park is allowed from 5 years old. Details differ by tour, so check the specific tour page for the exact age cut-offs and prices.
Can you swim everywhere in the park?
No, swimming is not allowed in the Emerald Lake on Mae Ko to protect the lake's ecosystem, though you can swim at the beaches and snorkel over the reefs. The lake is viewed from a platform at the top of a stairway instead.
Facts checked against our tour pages on 16 October 2026. Prices and days can change: your manager confirms them when you book.