Koh Kradan, Sunset Beach
Koh Kradan is the most popular beach in the Trangar chipelago, but 90% of the land is protected by Hat Chao Mai national park, which means hoteliers can’t develop there.KradanBeach (nicknamed Sunset Beach) is a skinny, one-mile palm-fringed strip of sand, but at low tide the Andaman Sea recedes to reveal numerous wide, white sandbars. Beach lovers can wade far out to sea, and pick their own private sandbar where they can catch some rays. Koh Kradan is a secluded and romantic place; there are no bucket bars or beach parties. The numerous cashew trees in the area give the air a sweet fragrance.Railay Beach, Krabi
Accessible only by boat (and located 45-minutes from Phuket), Krabi feels like a private island, complete with hidden coves and inlets. The beach is surrounded by towering limestone cliffs, and don’t be surprised to see locals practicing some free-form diving off of these CGI-looking marvels. Rock climbing, snorkeling, kayaking, and windsurfing are popular recreation activities in the area. West Railay Beach is home to a small promenade with shops and restaurants. There are more than 130 islands surrounding Krabi, and a longboat can take you out for a day of exploring.Maya Bay, Koh Phi Phi
Koh Phi Phi is a beautiful, can’t miss island. It has beaches that cater to every taste; thereare secluded coves for afternoon sunbathing, enough high-octane water activities to keep Richard Branson happy, and late-night beach parties for the international backpacker set. However, people flock to Koh Phi Phi because Maya Bay is only a quick boat ride away. For those who aren’t in the know, Maya Bay is where Leonardo Di Caprio’s The Beach was filmed, and it’s one of the most dramatic stretches of sandin Thailand. The powdery, crescent-shaped beach is ringed by mangroves and limestone cliffs, and the water is so crystal-clear, you can see colorful marine life swimming by your feet. 
Haad Sai Yao, Koh Muk
Nicknamed Haad Farang (farangis Thai for foreigner), this striking bay is framed by jungle foliage and limestone karsts. And while foreigners frequent this secluded andserene swath of sand –it’s popular with families because the water is free of dangerous riptides, and backpackers like the area because it’s off the beaten path the–after-hours scene is mellow, there are small bungalows instead of mega-resorts, and the crowds are thin in comparison to Thailand's most popular beaches. Accessible by sea kayak, the highlight of Haad Farang is Tham Morakot –the "Emerald Cave." Like a scene out of an Indiana Jones film, a winding stalactite cavern opens into a covewalled with jungle foliage, where monkeys can be seen swinging and frolicking about. 
Koh Lanta
Described as the bestall-roundisland in Thailand, Koh Lantais like a greatest hits version of what the country has to offer. Perhaps that’s because Koh Lantais actually comprised of several little islands, Koh LantaYai being the largest and most visited. Free from bright neon lights and big hotels, Koh Lantahas a colorful, laid-back vibe. There are fringes of sand where you won’t see another soul, dramatic rockery, nature reserves, friendly fishing villages, and gin-clear water. It’s unspoiled, but not untouched; accommodations run from spare to swanky, and there are funky beach bars made of driftwood and palmfronds, world-class diving, and excellent restaurants. 