Ko Lanta

Ao Nui
photo by flickr user furibond

A popular island off the south coast of Thailand in the Krabi Province. The main island is 6km wide and over 30km long.

The island only lately became one of the major tourist destination in Thailand. It is more more of a family destination than the nearby the Ko Phi Phi which is more popular with the younger crowd.

Wikitravel says:

Ko Lanta is popular with tourists seeking a holiday away from the parties. It’s popular with a significantly older crowd than nearby Ko Phi Phi: more walking on the beach and watching the sunset than drinking and dancing. However, there are plenty of bars and the longer term stayers are friendly and know how to party! It is also popular with families with young children, and of course, with divers.

Wikipedia says:
Ko Lanta (Thai: เกาะลันตา, also Koh Lanta) is a district (amphoe) in Krabi Province, Thailand. Tourism on Ko Lanta, like the rest of Krabi province, has exploded only very recently. In the early 1990s only the most adventurous travelers visited the island, staying in only the most basic accommodation costing the likes of 50-100baht a night. Nowadays, however, the place has turned into one of the major destinations for visitors to Krabi. The development however, is still nothing on a par with the likes of Phuket or Ko Samui. ... read more