Phang-Nga Province

National Park

This beautiful 70-sq-km marine national park is known to divers the world over. Lying 70km offshore from Phang-Nga Province, it has smooth granite islands that are as impressive above the bright-aqua water as they are below, topped with rainforest, edged with blindingly white beaches and fringed by coral reefs. Coral bleaching has killed off many of the hard corals, but soft corals are still intact, the fauna and fish are still there and it remains a lovely (and popular) place to dive.

National Park

Sitting 60km offshore, 5km from the Thailand–Myanmar marine border, are the five gorgeous isles of this marine national park. Healthy rainforest, pockets of white-sand beach in sheltered bays and rocky headlands that jut into the ocean characterise these granite-outcrop islands. Perfectly clear water makes for easy marine-life spotting, with underwater visibility of up to 30m outside the monsoon. Divers will have a field day, but this is also one of the finest spots for snorkelling in all of Thailand.

Island

Twin Peaks at Ko Tachai is one of the best dive sites on the Similans, although strong currents mean it is generally reserved for experienced divers. Expect to see big fish: manta rays and leopard sharks, as well as turtles. Ko Tachai is periodically closed to day trippers in response to growing environmental concerns; dive boats can still do dives here while remaining offshore.

Island

In 1998, the Similan Islands Marine National Park was expanded from its original nine islands to include uninhabited Ko Bon and Ko Tachai. The west ridge of Ko Bon is the number-one place in Thailand to see manta rays, as the coral is still in fine condition and so attracts many fish. Currents here can be strong, so it is often best for experienced divers.

National Park

Established in 1981, 400-sq-km Ao Phang-Nga National Park is famous for its classic karst scenery. Huge vertical cliffs dominate its 42 islands, some with caves that lead into hidden hôrng (lagoons surrounded by solid rock walls). The bay is composed of large and small tidal channels (Khlong Ko Phanyi, Khlong Phang-Nga, Khlong Bang Toi, Khlong Bo Saen), which run north to south through vast mangroves and function as aquatic highways. These are Thailand's largest remaining primary mangrove forests.

Lake

This stunning 165-sq-km lake sits 65km east (an hour’s drive) of Khao Sok National Park Headquarters. It was created in 1982 by an enormous shale-clay dam called Ratchaprapha (Kheuan Ratchaprapha or Chiaw Lan). Limestone outcrops protruding from the lake reach up to 960m, over three times higher than Phang-Nga's formations. Most lake visits involve a day or overnight tour (including transfers, boats and guides).

National Park

Immediately south of Hat Khao Lak, this vast 125-sq-km park is a collage of sea cliffs, 1000m-high hills, beaches, estuaries, waterfalls, forested valleys and mangroves. Wildlife includes hornbills, drongos, tapirs, serows, monkeys, Bengal monitor lizards and Asiatic black bears.

Buddhist Site

This unusual Buddhist complex (the name means 'Heaven and Hell' temple) has cave shrines, a dragon tunnel and a collection of grotesque figures representing life in hell for sinners. Children may be taken aback by the sometimes brutal depictions that appear better suited for a haunted house. Climb a steep staircase to reach a pavilion affording awesome views of the valley.

Cave

Reached on foot from the southwestern shore of Chiaw Lan Lake, Tham Nam Thalu contains striking limestone formations and subterranean streams. It is only partially accessible during the rainy season and we don't recommend visiting then; there have been fatalities due to flash flooding. You'll need a guide (per day 1200B) at any time of year; this can be arranged at the Khao Sok National Park Headquarters.