The 42 Islands of Ang Thong Explained

Forty-two limestone islands, about 18 km² of land, and a day trip that lands on two to four of them. Here is what each named island is for, which ones you cannot visit, and what the park really has to do with The Beach.

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Forty-two islands, and the handful you will see

Mu Ko Ang Thong National Marine Park is officially an archipelago of 42 islands spread across 102 km² of the Gulf of Thailand. It became Thailand's 21st national park on 12 November 1980 and a Ramsar Wetland of International Importance (Site No. 1184) in 2002. A day trip lands on two to four of the islands: Koh Wua Talap for the viewpoint, Koh Mae Ko for the Emerald Lake, and a snorkelling stop or two. The rest are uninhabited limestone outcrops with no facilities, and only licensed operators may take you into the park. The Ang Thong day tour with kayak, snorkel and lunch covers both headline islands from $68.

Book the Ang Thong day trip — from $68 See the islands one by one

Park figures from Thailand's Department of National Parks, thainationalparks.com and the Ramsar Sites Information Service. Tour prices and ratings checked on GetYourGuide, 11 October 2026.

Live availability — the Ang Thong day trip

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The Count, the Area and the Rock

Three facts that guidebooks often get wrong.

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The Count Is 42, Every Time

The Department of National Parks (DNP), the Ramsar Convention Secretariat and mainstream references all give 42. The Ramsar sheet for Site No. 1184 calls the park "a complex of 42 small islands in the Gulf of Thailand, including sandy beaches, rocky cliffs, coral reefs, and young mangrove forests." What varies is which rocks and stacks count as islands. Printed sources name only about nine to twelve of them, so any list claiming all 42 names is made up.

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102 km² in Total, About 18 km² of Land

The park covers 102 km² (63,750 rai), and the islands themselves only about 18 km²; the rest is open water and reef. Wikipedia's widely copied "about 50 square kilometres (19 sq mi) are land" looks like a mistranscription, with a land figure of about 19 km² read as 19 square miles and converted. The DNP portal and thainationalparks.com both put the land at about 18 km².

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Permian Limestone, Shaped by Rain

The islands are tower karst cut from limestone of the Ratburi Group, laid down roughly 286 to 245 million years ago when the region lay under a shallow tropical sea. Uplift and millions of years of rain dissolved it into the cliffs, sea caves, sinkholes and inland marine lakes you see today. Phang Nga Bay and Krabi on the Andaman coast formed the same way.

Other Experiences You Might Enjoy

More ways into the archipelago, and beyond it.

Most visitors see the Ang Thong Marine Park islands on a boat day from Koh Samui or Koh Phangan: the viewpoint on Koh Wua Talap, the Emerald Lake on Koh Mae Ko, and kayaking and snorkelling around Koh Sam Sao and Koh Wao. If you have more days, the reefs at Koh Tao and Koh Nang Yuan and the half-day to Pig Island are close by. Live options are below.

What "Ang Thong" Means

A golden bowl, and not the province near Ayutthaya.

"Ang Thong" (อ่างทอง) means golden bowl or golden basin: ang is a bowl or basin, thong is gold. "Mu Ko" (หมู่เกาะ) means a group of islands. People explain the name three ways: the bowl shape of the hidden lagoon on Koh Mae Ko, the amber glow the limestone takes on at sunrise and sunset, or the general natural wealth of the archipelago. A local legend says the islands were once a giant who turned to stone.

The marine park shares its name with Ang Thong Province in central Thailand, near Ayutthaya, but the two have nothing to do with each other. The province is rice country, and its "golden bowl" refers to the paddy fields. Visitors mix them up often, so if you are booking transport, check that the place on the ticket is the Gulf of Thailand and not a town north of Bangkok.

How the Islands Became a Park

From a navy base and fishing grounds to an ASEAN Heritage Park.

Before the park existed, the Royal Thai Navy used the islands and kept a base in the area, and fishing communities settled parts of the archipelago. Popular accounts describe its caves and channels as shelter for pirates and traders crossing the Gulf. Islanders planted coconuts, fished, and held licences to collect edible swiftlet nests, mostly on Koh Phaluai.

1

1975 — The proposal

A Thai forestry scientist proposes protecting the archipelago as a marine park.

2

12 November 1980 — National park

A royal decree makes Mu Ko Ang Thong Thailand's 21st national park, covering 102 km² in Surat Thani Province.

3

14 August 2002 — Ramsar site

The park is listed as Ramsar Wetland of International Importance Site No. 1184.

4

2019 — ASEAN Heritage Park

The park joins the ASEAN Heritage Parks network.

The Named Islands, One by One

Five islands carry almost every tour. Seven more have names and little else.

Park headquarters

Koh Wua Talap (เกาะวัวตาหลับ) — "Sleeping Cow Island"

Viewpoint trailBua Bok CaveBungalows & camping

The most visited island, with the visitor centre, ranger station, a restaurant and shop, bungalows and a camping ground at Ao Phi/Kha Bay. Its signature is the Pha Chan Charat ("Jan Jaras") viewpoint trail: about 500 metres of steep trail with rope-assisted sections to a panorama over the whole archipelago, one of the most photographed views in Thailand. The park puts the climb at about 25–30 minutes; slower walkers take up to 45. The island also has Bua Bok Cave (Lotus Cave), a stalactite and stalagmite cave reached by a short hike, and a small museum with a whale skeleton. Dusky langurs are often seen around the ranger station. Our Koh Wua Ta Lap guide covers the climb step by step.

The Emerald Lake

Koh Mae Ko (เกาะแม่เกาะ) — "Mother Island"

Thale Nai lagoonNo swimmingStair climb

Home to Thale Nai, the Emerald Lake or Blue Lagoon: an inland saltwater lake in a collapsed limestone sinkhole, fed from the sea through underground channels. Bangkok Airways' official blog puts it this way: "Thale Nai measures 250 meters wide and 350 meters long with a water depth of 7 meters," an area of about 65,600 m². Swimming is banned to protect the lagoon; you look down on it from a raised platform at the top of a stair climb. It is the second of the two viewpoint stops on a standard tour. More in our Koh Mae Ko guide and the Blue Lagoon explainer.

The largest island

Koh Phaluai (เกาะพะลวย)

About 19.1 km²Fishing villageSeafood lunch stop

The biggest island and the only one with a real population: a fishing village in the Ban Ao Sam area of roughly 450–500 people, mostly fishing families sometimes called "sea gypsies". It is the administrative centre of the island chain within Ang Thong Subdistrict, Ko Samui District, Surat Thani. Only the northern part lies inside the park and it is mostly undeveloped; the south has the villages, a school, a police post, a shop and small resorts and homestays, largely on solar power. The island keeps some of the best remaining mangrove in the Gulf, and many tours stop here for a seafood lunch. The park's highest point, 396 m, is generally attributed to Koh Phaluai.

Arch & reef

Koh Sam Sao (เกาะสามเส้า) — "Three Pillars" or "Tripod" Island

Stone arch~1 km of reefCampsite

Known for a natural stone arch reaching out into the sea, a short viewpoint trail, a campsite, and snorkelling over roughly 1 km of coral reef. It sits northeast of Koh Mae Ko and is a regular kayaking and snorkelling stop. Our Ang Thong snorkelling guide compares the reef stops.

Sheltered snorkelling

Koh Wao (เกาะวัว) — also Koh Wao Yai or Koh Kite

Three isletsCalm baySea caves

A cluster of three tiny islands around a calm bay, which gives reliable snorkelling all year and sea caves you can swim through. It is a common first snorkelling stop and sits at, or just outside, the edge of the core park zone.

Rarely landed on

The other named islands

SceneryBirdlifeReefs

Koh Hin Dap, Koh Nai Phut, Koh Phai Luak, Koh Wua Kantang, Koh Ka and Koh Wua Chio appear again and again among the park's "important islands" in park and tour material, but have little or no visitor infrastructure. Most are rocky karst outcrops that matter for their scenery, birds and surrounding reefs. Koh Tai Plao, a scenic snorkelling island, turns up on some island-hopping itineraries.

The Ang Thong speedboat day tour visits the Koh Wua Talap viewpoint and the Koh Mae Ko lagoon and adds kayaking and snorkelling, from $68 at 4.69/5 from 2,146 reviews.

Which Islands You Can Visit, and Which You Cannot

Licensed operators only, and most of the park is a no-development zone.

StatusIslandsWhat it means for you
Developed for visitorsKoh Wua Talap (HQ, viewpoint, cave), Koh Mae Ko (Emerald Lake), Koh Sam Sao (arch, snorkelling), Koh Wao (snorkelling caves), Koh Phaluai (lunch, fishing village)The standard tour stops. Most day trips visit two to four of them.
Restricted and protectedMost islandsThe DNP enforces no-development zones that forbid land possession, forest clearing, burning and taking resources. Swimming in Thale Nai is banned.
Rarely visitedThe majority of the 42Remote karst outcrops with no facilities and no regular visitor access.

You can only enter the park with a government-licensed tour operator; there is no independent access. The national park fee is 300 THB per foreign adult and 150 THB per child, often paid on the day. Our getting there guide explains the departure piers, and the best tours roundup compares the operators.

Sleeping on the Islands

Park bungalows on Koh Wua Talap, or a small resort on Koh Phaluai.

Park bungalows and camping, Koh Wua Talap

The Department of National Parks rents bungalows at 600 THB a night for two people and 1,500 THB for eight, and camping costs 80 THB per person, with tents for hire at 450 THB (thainationalparks.com). The DNP online booking system has had long outages and was down as of June 2026, so you will usually need to arrange a stay directly with the park or through a tour operator. No tour on GetYourGuide sells an overnight package; the park books these itself.

Resorts and homestays, Koh Phaluai

The village on the southern half of Koh Phaluai, outside the protected northern zone, has a few small resorts and homestays. Angthong Beach Resort is one that takes bookings on Booking.com. You can also search all stays on Koh Phaluai. Getting there means arranging a boat, since day tours return to Koh Samui or Koh Phangan in the afternoon.

The Ramsar Wetland Listing

Why a park of limestone islands counts as a wetland.

Ang Thong was registered on 14 August 2002 as Ramsar Site No. 1184, a Wetland of International Importance covering the 102 km² marine zone. The listing recognises its coral reefs, young mangrove forests, seagrass beds and beach forests, and its role as a breeding and nursery ground for commercially important fish, above all the Indo-Pacific mackerel (Rastrelliger brachysoma).

The Ramsar sheet is frank about the water. It is shallow and often cloudy with sediment, much of it from the Tapi River, which limits coral growth and diving visibility. That is why snorkelling here is about the scenery around you as much as the reef below; our diving guide explains what visibility to expect. The same sheet notes that "the area draws more than 50,000 Thai and international visitors per year for recreation and ecotourism." Treat that as the baseline at the time of listing: more recent estimates put annual visits considerably higher.

Ang Thong is one of a group of Thai coastal marine parks that are Ramsar sites, alongside Ao Phang-nga, Laem Son and Hat Chao Mai.

Plants and Wildlife

Langurs on the trail, hornbills overhead, and an orchid tour guides usually misname.

  • Vegetation: dry evergreen forest on the larger islands, limestone forest and scrub, cacti and succulents on exposed rock, and small stands of planted mangrove along beaches and bays. Over 175 plant species have been recorded.
  • Mammals (about 16 recorded species): dusky langur (also called the dusky leaf monkey or spectacled langur), long-tailed macaque, leopard cat, fishing cat, wild boar and smooth-coated otter. The park says its lists are incomplete.
  • Birds (about 50 species): oriental pied hornbill, collared kingfisher, white-bellied sea eagle, brahminy kite, black baza, Pacific reef egret (reef heron), edible-nest swiftlet and common hill myna.
  • Reptiles and amphibians: about 14 reptile and 5 amphibian species, including monitor lizards, pythons and sea turtles.
  • Marine life: sources cite roughly 38–54 species of hard coral; reef fish including clownfish, parrotfish, angelfish and butterflyfish; the odd green sea turtle; and dolphins, including sightings of the pink Indo-Pacific humpback dolphin.
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    The Ang Thong Orchid, Correctly Named

    Tour material calls it the "Ang Thong Lady's Slipper" and uses names such as "Paphiopedilum angthong" or "Paphiopedilum niveum". Both are wrong. The accepted name is Paphiopedilum godefroyae var. ang-thong (Fowlie) Braem: Plants of the World Online (Royal Botanic Gardens, Kew, ID 954773-1) lists "Paphiopedilum ang-thong Fowlie", published in 1977, as a synonym. It is a variety of P. godefroyae, not a species of its own, and not a form of P. niveum, a separate white-flowered species from the Langkawi and Tarutao area.

    Its range is peninsular southern Thailand, and the wider godefroyae group also grows elsewhere, for example on the Bird's Nest Islands off Chumphon, so "found only at Ang Thong" overstates it. The parent species is Endangered on the IUCN Red List; the Encyclopedia of Life, citing the IUCN, describes it as "listed as endangered by IUCN and in cites appendix i." All Paphiopedilum are on CITES Appendix I, which bans international commercial trade in wild-collected plants. Look, photograph, and leave it where it grows.

    Ang Thong and The Beach

    The setting of the novel, but not where the film was shot.

    ClaimVerdictThe detail
    Ang Thong is in the novelTrueAlex Garland's 1996 novel The Beach is set in the Gulf of Thailand around Koh Samui, Koh Phangan and Surat Thani, and its characters camp on "Koh Angthong". The park's hidden lagoon is often credited as the model for the book's secret lagoon.
    Ang Thong was the only inspirationOverstatedGarland wrote the book while living in the Philippines and has said the geography of Palawan (El Nido) was a major inspiration.
    The film was shot at Ang ThongFalseDanny Boyle's 2000 film, starring Leonardo DiCaprio, shot its beach scenes at Maya Bay on Koh Phi Phi Leh in the Andaman Sea (Krabi Province), the waterfall jump at Haew Suwat Waterfall in Khao Yai National Park, and the backpacker scenes on Khao San Road, Bangkok.
    Some sequences were filmed at Ang ThongUnsupportedThe claim circulates on tourism sites but no documented filming location backs it.

    So when a tour calls Ang Thong "the beach from the movie", read it as "the setting and inspiration for the novel". That part is true.

    What Changed in 2024–2026

    An annual closure, a bleaching year, and a booking system that keeps failing.

  • Annual closure. The park closed from 1 November to 15 December 2025 for its yearly monsoon-season restoration. The reopening date moves with the weather, historically anywhere from about 10 to 20 December and occasionally later. Our best time to visit guide tracks the dates.
  • 2024 mass coral bleaching. A regional bleaching event hit the Gulf of Thailand in 2024. Ramkhamhaeng University's Marine Biodiversity Research Group, led by Prof. Thamasak Yeemin, has published assessments of the damage at neighbouring western Gulf parks such as Mu Ko Chumphon, and its monitoring since 2024 covers reefs like Ang Thong's.
  • Coral recruitment. Field surveys in Mu Ko Ang Thong have recorded up to about 26 juvenile corals per m², a sign that the park works as a natural coral nursery. Park managers have used the data to revise reef zoning and tourism controls.
  • Booking system. As of 2026, the DNP's online accommodation booking has suffered long outages, which makes it hard to reserve the Koh Wua Talap bungalows and campsite. Arrange directly with the park or through a tour operator.

    • Tours That Reach the Main Islands

    Most day trips stop at Koh Wua Talap and Koh Mae Ko. The boat you choose sets how long you get at each.

    Choose the speedboat if the viewpoint and lagoon are the point of the day, the big boat if price or a calmer ride matters more. For a smaller group, the semi-private yacht adventure runs from $128 at 4.84/5 from 1,926 reviews. Staying on Koh Phangan? The Ang Thong day tour from Koh Phangan runs from $78 at 4.54/5 from 1,079 reviews. Prices and ratings checked on GetYourGuide, 11 October 2026.

    Where the Sources Disagree

    The figures to treat as approximate.

  • The island count. 42 is official and consistent, but no source gives a complete named list. Only about nine to twelve islands are ever named individually.
  • Land area. You will see both about 18 km² and about 50 km². The 50 km² figure is a mistranscription; use about 18 km² for land and 102 km² for the whole, mostly marine, park.
  • The highest point. 396 m is cited consistently but not always for the same island. Koh Phaluai is the usual attribution.
  • Wildlife lists. The park says its lists are incomplete, and "recorded" species are not the same as species likely present.
  • Filming at Ang Thong. Some tourism sites repeat it; the film's documented locations are Maya Bay, Khao Yai and Bangkok.
  • Koh Phaluai's population ranges from about 450 to about 500 across sources.
  • The orchid. Several tourism sources confuse Paphiopedilum niveum with the Ang Thong plant. They are different taxa, and "Paphiopedilum angthong" is not an accepted species name.
  • Visitor numbers. The Ramsar sheet's "more than 50,000 per year" is a baseline; current visits are likely much higher.

    • Common Questions

    Forty-two. Thailand's Department of National Parks and the Ramsar Convention both give the same figure, and it has not changed in decades. Only about nine to twelve of the islands have names you will find in print, and a standard day trip lands on two to four of them. The rest are small, uninhabited limestone outcrops.
    The usual stops are Koh Wua Talap, the headquarters island with the viewpoint trail and Bua Bok Cave; Koh Mae Ko, for the Thale Nai lagoon; Koh Sam Sao, for its stone arch and reef; Koh Wao, for sheltered snorkelling; and Koh Phaluai, where many tours stop for a seafood lunch. Most trips cover two to four of these, so check the itinerary before you book.
    No. Alex Garland's 1996 novel names Ang Thong and is set around Koh Samui, Koh Phangan and Surat Thani, but the 2000 film starring Leonardo DiCaprio shot its beach scenes at Maya Bay on Koh Phi Phi Leh, the waterfall jump at Haew Suwat Waterfall in Khao Yai National Park, and the backpacker scenes on Khao San Road in Bangkok. Garland has also said the geography of Palawan in the Philippines inspired the book.
    No. Swimming in Thale Nai is banned to protect the lagoon's ecosystem. You see it from a raised platform at the top of a stair climb. The lagoon is about 250 metres wide and 350 metres long, with water 7 metres deep, and it connects to the sea through underground channels.
    Yes, on Koh Wua Talap. The Department of National Parks rents bungalows at 600 THB a night for two people and 1,500 THB for eight, and camping costs 80 THB per person, with tents for hire at 450 THB. The park's online booking system has been down since at least June 2026, so arrange a stay directly with the park or through a tour operator. Small resorts and homestays also operate in the village on the southern part of Koh Phaluai.
    Every year during the monsoon. In 2025 the park closed from 1 November to 15 December for seasonal restoration. The reopening date moves with the weather, historically anywhere from about 10 to 20 December and occasionally later, so check the national park announcements before booking a December trip.
    Steep but short. The trail is about 500 metres long, with steps and rope-assisted sections. The park puts it at about 25 to 30 minutes up; slower walkers take up to 45. Wear shoes with grip, carry water and start early, before the midday heat.
    Golden bowl, or golden basin: ang means bowl and thong means gold. Mu Ko means a group of islands. The name is explained as the bowl shape of Koh Mae Ko's lagoon, the amber glow of the limestone at sunrise and sunset, or the general richness of the archipelago. It has nothing to do with Ang Thong Province near Ayutthaya, a rice-farming province with the same name.

    See the Islands From the Water

    Compare the Ang Thong day tours: boat type, group size, which islands they stop at, prices and free-cancellation policies.

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