The Similan Islands are a group of islands located in the Andaman Sea, off the coast of Thailand. They are part of the Mu Ko Similan National Park, which was established to protect the area's unique marine ecosystem. The islands are known for their stunning beaches, crystal-clear waters, and diverse marine life, making them a popular destination for snorkeling and diving. The Similan Islands consist of 11 islands, with the largest being Ko Similan. The islands feature granite boulders, lush forests, and vibrant coral reefs. The best time to visit is between November and May, when the weather is dry and the sea conditions are ideal for exploring the underwater world.