Koh Lanta Similan Islands. Ko Lanta (also spelt Koh Lanta) is one of Thailand's most beautiful islands, located just off the coast of Krabi. The Similan Islands is an archipelago in the Andaman Sea off the coast of, and part of, Phang Nga Province in southern Thailand.
The largest island is Koh Similan and is probably the best place to start your adventure. The Similans are famed for their spectacular underwater scenery and marine life, and is regarded as one of the top ten dive spots in the world. Probably because it's not so Koh Lanta is formed also by Koh Lanta Noi.
It has resisted rapid tourist development like no other island in the country.
I'd put it on the same level as Koh Mak and Koh Kood but unfortunately this place gets so much.
The tourist season in Ko Lanta runs from October. The ideal time to visit Similan Islands is December to April when it is the dryer with clear waters making it best time for scuba diving and snorkelling. Probably because it's not so Koh Lanta is formed also by Koh Lanta Noi.