Ang Thong Marine National Park
A UNESCO-protected archipelago of 42 limestone islands in the Gulf of Thailand — Ang Thong's Emerald Lake, sea caves, kayaking routes, and coral reefs inspired Alex Garland's novel The Beach.
About this Place
Ang Thong — meaning Golden Basin — is a protected national marine park comprising 42 limestone islands rising dramatically from the Gulf of Thailand, clearly visible from Koh Samui's west coast on a clear day. The archipelago inspired Alex Garland's cult novel and film The Beach, and it retains the untouched, otherworldly quality that made that story resonate globally. The park's centrepiece is the Emerald Lake (Thale Nai) — a landlocked saltwater lagoon of brilliant green water hidden inside Ko Mae Ko island, reached by a steep but manageable viewpoint trail. Beyond the lagoon, the park rewards exploration with sea caves accessible by kayak, dramatic sea arches framing open water, snorkeling reefs with intact hard coral and abundant marine life, and elevated viewpoints with sweeping panoramas across the entire archipelago. Day tours depart from Koh Samui's Na Thon Pier and from Koh Phangan. Overnight camping is possible on Ko Wua Talap island. The park has no permanent human population. It closes June through October due to heavy monsoon seas. March through May offers the clearest water and calmest conditions. National park entrance fees apply on all tours.
Location
9.7590, 100.0220
More Nearby Locations
Koh Samui's iconic golden 12-metre Buddha sits on a small islet connected by a causeway lined with naga serpents. An active monastery with sea views, souvenir stalls, and ferry access to nearby islands just steps away.
Koh Samui's iconic 8km white sand beach with calm turquoise waters ideal for swimming, paddleboarding, and kite surfing by day — and a buzzing strip of beach bars, clubs, and restaurants by night.
Koh Samui's most charming neighbourhood — century-old Chinese shophouses line a quiet beachfront, home to boutique cafes and galleries by day, and a beloved Friday night market with street food and live music by evening.
Twin jungle waterfalls in Koh Samui's interior — the purple-tinged Na Muang 1 offers a natural swimming pool after a short walk, while the taller Na Muang 2 rewards a 1.5km jungle hike through dense rainforest.