Thailand has three main sets of islands; those to the east of Bangkok, between Bangkok and the Cambodian border; those in the southern Gulf of Thailand; and those in the Andaman Sea -- off the west coast of Thailand, between the Burman and Malaysian frontiers.

We've also covered a smattering of the lesser known islands that you probably won't read about in your guidebook -- in our opinion these can be some of the best islands in Thailand.

Koh Adang

Thailand's remote Ko Adang is an ideal island for nature-loving travellers who seek a less-populated haven well away from peak-season beaches packed with sunbathing limbs. With plenty of hiking trails, deserted white sand beaches and jungle waterfalls there's enough here for day-trippers from nearby Ko Lipe along with those who plan to spend a longer stretch of time exploring all this island has to offer.

Koh Bulon Lae

While under the radar for many, little-known Ko Bulon Lae remains popular with returning vacationers (particularly families) year after year. Bungalow resorts are scattered around the island, so choices are as varied as the travellers who stay here: windy hillsides, beaches with or without rocks and mangroves, forested or exposed to sun and salty air. Every night, the generators switch on and Bulon lights up for another laid-back evening. Many travellers come back again and again, to find the particular tranquility they've only found on Bulon.

Koh Kradan

A Thai island with so much potential, the beauty and tranquility of Ko Kradan has been squandered over the last decade and it remains best-known for its annual mass underwater-weddings rather than the stunning beach and large coral reef. The view from the beach is spectacular, looking out and over other islands including Ko Muk. If you are in the area, it's definetly worth coming out here -- but for the moment, a day-trip remains the best option.

Koh Kut

Despite being a beautiful mountainous island with white sandy beaches and crystal blue water, for the independent traveller, Ko Kut can be a difficult destination to explore -- though for some that just adds to the attraction. Popular with Thai package tourists, Ko Kut is a terrific island to escape the hordes of foreign tourists and experience some of the hospitality Thailand is famous for.

Koh Lanta

For a long time Ko Lanta was a little-visited backpacker spot in Thailand, playing second fiddle to the big backpacker magnets of Ko Pha Ngan, Ko Tao and Raileh Beach. But word has finally got out about what a great island Ko Lanta truely is -- with something for just about every budget -- from high class luxury to basic thatch huts. With a less hectic scene, smooth, calm waters and broad beaches, Ko Lanta is particularly popular with those travelling through Thailand with young children.

Koh Libong

This large island sits quite close to Thailand's southwest coast in Trang province. Little-visited, Ko Libong is much cleaner than some of its neighbours, the people are polite, honest, friendly and eco-minded. Fewer visitors make it here, but those that do are generally well-rewarded. A nice laid back kind of place that doesn't have the jaded feel of some other busier Thai islands. Oh, and there's dugongs here too.

Koh Lipe

A warm, windy island that offers something for most anyone, Lipe's range of accommodation options and fantastic marine life attract a healthy (and rapidly increasing) number of tourists each year. Still, it's easy to find tranquil surroundings here, even during peak season, with several coves and walks through the jungle from one beach to another. Rapidly increasing in popularity, see Lipe now while it still retains some of its beauty.

Koh Maak

Just to the south of Ko Chang, Ko Maak is a lot less heavily touristed than its big sister -- a great place to go for a bit of quiet and some less crowded beach front: perfect just for chilling out. The two main beaches are sandy, scattered with rock, and sparsely populated with bungalows. The relatively flat interior is covered with coconut palms and a maze of unsignposted dirt roads. A laid-back hideaway.

Koh Tao

Over the years, Ko Tao has been a pirate's hideout, a layover for fishermen, a prison and a badly-kept backpacker secret. Today it is one of Thailand's premier diving locations, attracting thousands of recreational divers and other tourists annually. The island is ranked number two worldwide for the issuing of PADI certificates. Non-divers willing to escape from the congested diver hotspots are rewarded with gorgeous beaches, great viewpoints and hospitable locals. Of course if you are diving, Ko Tao is a must, with some of the best diving in the Gulf of Thailand.

Koh Tarutao

In Malay, Tarutao means old, mysterious and primitive. For many visitors, Tarutao's appeal is in the wildlife: sea turtles, whales, monitor lizards, crab-eating macaques, mouse deer and more all call the island and its surrounding waters home. There's no snorkeling as the waters are murky compared to other Andaman islands, but for most, the clean beaches, waterfalls, great hiking and views more than compensate. For those who are into such things, Ko Tarutao was the location where Thailand Survivor was filmed.