A white sand beach curving towards a forested headland, with clear turquoise water and overhanging leaves

Island · Phang Nga Province, Andaman Sea

Similan Islands

A protected chain of granite islands 70 km off Phang Nga, with white beaches, giant boulders and renowned dive sites

Ambient sound · similar settingWaves breaking on an Indian beach

Photo: Valeria Hutter (@valeria_h) / Unsplash

Discover Similan Islands

The Similan Islands lie around 70 kilometres off the coast of Phang Nga, a line of small islands that look quite unlike the limestone scenery elsewhere on the Andaman coast. Here the rock is granite, weathered into enormous smooth boulders that pile up along the shore and continue underwater, forming swim-throughs, arches and reefs. Beaches of fine white sand meet water that is often startlingly clear.

The islands are numbered from south to north, and only some are open to visitors; several are closed to protect turtle nesting beaches and reefs. Most people come on a day trip by speedboat from Khao Lak, snorkelling at a few sites and walking up to viewpoints such as the one above Ko Similan's main bay. Divers come for longer on liveaboard boats, exploring sites around the islands and Ko Bon.

Don’t miss

01Snorkelling over coral and granite boulders in very clear water
02The viewpoint above the main bay on Ko Similan
03Liveaboard diving at sites around the islands and Ko Bon
04Turtle nesting beaches protected from visitors
05Wildlife such as Nicobar pigeons on the islands

History & culture

The story of Similan Islands

The name is generally explained as coming from the Malay word for nine, after the original number of islands. The area was declared Mu Ko Similan National Park in 1982 after a year-long assessment, and Ko Bon and Ko Tachai were added in 1998, bringing the number of islands to 11.

Visitor numbers rose quickly, reaching several thousand a day in the 2010s and damaging reefs and beaches. Ko Tachai was closed to tourists in 2016, overnight accommodation was later removed from the islands, and since 2018 the park has capped daily visitor numbers. Each year the park closes for five months during the south-west monsoon to allow the marine environment to recover.

Local life & traditions

The islands themselves have no permanent villages; life around the park is centred on the mainland at Thap Lamu and Khao Lak, where fishing families, boat crews, dive instructors and guides depend on the season. Southern Thai seafood is easy to find in local restaurants near the pier.

Things to do

Experience it like a local

Speedboat day trips from Thap Lamu pier near Khao Lak typically visit two or three islands, with snorkelling stops over the reefs and time on a beach. On Ko Similan, the largest island, a short trail climbs over the boulders to a viewpoint above the main bay. Divers can join day trips or multi-day liveaboards, which reach the more distant sites and allow early-morning dives before the day boats arrive. There are no hotels on the islands, so visitors return to the mainland each evening.

When to go

The park opens only between mid-October and mid-May. Visibility and sea conditions are generally best from December to April, which is also the main liveaboard season. The park is closed from mid-May to mid-October during the south-west monsoon.

Plan your visit

Verified information

Season (2026–27): The park reopened on 15 October 2026 for a season running to 15 May 2027, after the monsoon closure from 16 May to 14 October 2026. Source: pattayamail.com ↗
Monsoon closure (2026): The Department of National Parks closed the Similan and Surin islands to tourism and overnight stays for five months from mid-May to mid-October 2026, for safety in the monsoon and to let nature recover. Source: region1.prd.go.th ↗
Getting there: Boats leave from Thap Lamu pier, about 13 kilometres from Khao Lak; the crossing takes around 70 minutes by speedboat or about three hours on a standard boat. Source: en.wikipedia.org ↗
Accommodation: There is no overnight accommodation on the islands; visitors stay on the mainland, mostly in Khao Lak. Source: en.wikipedia.org ↗

Checked against the sources on 29 October 2026. Opening times and fees can change — confirm before you go.

Travel tips

Plan your trip between mid-October and mid-May; the park is closed for the rest of the year.
Book with a licensed operator, as the park limits the number of visitors each day.
Use coral-safe sunscreen and wear a life jacket on the boat, as park rules require.
Do not stand on or touch coral when snorkelling.
Expect a long day: pick-ups from Khao Lak and Phuket hotels start early.

General guidance from our specialists, not official information.

Around Similan Islands: food, markets & places to stay

Khao Lak, on the mainland opposite, is the main base for Similan trips and has many resorts along its beaches. The Surin Islands, another marine national park, lie further north. Khao Sok National Park is about an hour and a half inland, and Phuket is roughly two hours to the south by road.

Similan Islands & what’s nearby

All places in Thailand →

Loading map…

Open larger map ↗

Rounded, forested limestone islands scattered across a calm blue-green bay under a cloudy sky

Nature

Phang Nga Province, Andaman coast · 105 km away

Similan Islands in pictures

Aerial view of a wooded headland dotted with bungalows above a clear turquoise bay

Island

Ko Pha-ngan District, Surat Thani Province

Koh Tao

Koh Tao, 'Turtle Island', is a 21 square kilometre island north of Ko Pha-ngan whose economy revolves around diving. Clear, warm water, coral reefs close to shore and a large number of dive schools make it one of the most popular places in the region to learn to dive.

Explore

Visit Similan Islands on a Thailand holiday

All Thailand packages →

Drone view of boats on the turquoise water of Maya Bay, Phi Phi Island, between limestone cliffs.

BeachCulture

Thailand · 10 nights4★ Resort

Bangkok, Chiang Mai & Phuket

Grand Palace
Doi Suthep temple
Phi Phi Islands by speedboat

Includes accommodation · daily breakfast · domestic flights · private transfers

Indicative from

$2,138 pp

Gold and red temple buildings of Wat Phra Kaew at the Grand Palace under a blue sky.

BeachHoneymoon

Thailand · 7 nights4★ Resort

Bangkok & Krabi Beaches

Bangkok canals by longtail boat
Railay Beach
Four-island tour

Includes accommodation · daily breakfast · bangkok–krabi flight · private transfers

Indicative from

$1,439 pp

Sources & verification

This guide was researched from the sources below and reviewed by our team on 29 October 2026. Facts under “Verified information” link to the page they were checked on; travel tips are general guidance. Photos are credited on each image. The ambient recording’s author and licence are shown in the sound player.

Similan Islands — Wikipedia
Similan and Surin islands closed for five months — Public Relations Department, Region 1 (Thailand)
Similan Islands welcome 1,400 tourists on opening day — Pattaya Mail
Similan Islands closed for five months — Office of Natural Resources and Environmental Policy and Planning (ONEP)
Mu Ko Similan National Park — Thai National Parks

Want Similan Islands in your itinerary? Our specialists will fit it in.

Customise a Thailand trip Ask a specialist