Khao Sok National Park in Surat Thani protects one of the oldest rainforests in the world. Limestone peaks rise above jungle home to elephants, gibbons and the giant Rafflesia flower. Cheow Lan Lake, formed by the Ratchaprapha Dam in 1987, has floating raft houses among towering karst cliffs. Visitors trek, canoe and explore caves.

The Big Buddha of Ko Samui sits on Ko Faan, a small island linked by a causeway to the northeast coast of Samui. The golden seated Buddha, about 12 metres high, was built in 1972 and belongs to Wat Phra Yai. A stairway guarded by naga serpents leads up to it. It is a well known landmark for planes landing at the nearby airport.

Chaweng Beach is the longest and busiest beach on Ko Samui, running about six kilometres along the east coast. Its white sand and clear water are protected by a reef at the northern end. Hotels, restaurants and bars line the beach, and the street behind it is the centre of the island's nightlife. The southern end has rocky coves.

Mu Ko Ang Thong National Marine Park is a group of about 40 islands west of Ko Samui. Steep limestone islands covered with forest rise from the turquoise sea. On Ko Mae Ko, a path climbs to a viewpoint above Thale Nai, an emerald saltwater lake enclosed by cliffs. On Ko Wua Talap a steep climb leads to a view over the archipelago. Day trips leave from Samui.

Ko Pha Ngan is an island in the Gulf of Thailand north of Ko Samui. It is famous for the Full Moon Party held each month on Haad Rin beach in the south. The rest of the island is quieter, with forested hills, waterfalls and beaches such as Bottle Beach and Thong Nai Pan. Yoga and wellness retreats are common.

Ko Tao is a small island in the Gulf of Thailand north of Ko Pha Ngan. Its name means turtle island. It is one of the most popular places in the world to learn scuba diving, with warm clear water and coral reefs close to shore. Rocky coves, viewpoints and small beaches such as Sai Ree and Tanote Bay surround the island.

Ko Nang Yuan is a group of three small islands off the northwest coast of Ko Tao, joined by sandbars of white sand. A viewpoint at the top of one island gives the famous view of the sandbars curving between the turquoise bays. The islands are privately owned with one resort, and day visitors come for snorkelling over the coral reefs.