No resorts. No restaurants. No tour operators offering overnight trips (you'll have to arrange that ad hoc). But you can camp on the stunning twin islands of Koh Rok Nok and Koh Rok Nai in the Ko Lanta archipelago. Doing so gets you one of Thailand's very best beaches, Ao Sarn Chao, pretty much to yourself. The 100m swim between islands is a snorkelling paradise with 20m visibility over a mile-long coral reef.

Damneon Kasem Road leads from the station to another historic landmark: the colonial-style former Railway Hotel. Established in 1922, the Victorian-inspired building was the country's first resort hotel before being restored, wooden panels and all, and re-branded to the current Sofitel Central Hua Hin Resort. This is a good place for afternoon tea or a light snack, before strolling it off in the landscaped gardens among topiary elephants and other hedgerow animals.

Next door is an alleyway lined with stalls of tourist tat, leading to the inauspicious main entrance to wide, sweeping Hua Hin Beach, which lacks the palm-fringed romanticism of Thailand's islands. Nonetheless, it makes for a pleasant stroll, and you can always take up the offer of a pony ride along the sand. The sea here is usually pretty calm in low season (May to September), though windsurfers get some action when gusts kick up around year's-end.

This stretch is backed by the fancy summer homes of the Bangkok elite. Hua Hin has long carried an air of exclusivity. Some of these buildings date back a century, while Baan Bayan and Baan Talay Dao have been converted into boutique resorts. The royal presence, meanwhile, can be seen at the teak Mediterranean-style summerhouse Klai Kangwan Palace, built in 1926 for King Rama VII and still frequented by Thai royals.

When the afternoon sunlight begins to wane, head to Baan Itsara, a Thai restaurant set in a large old Thai house right on the beachfront. Despite exterior appearances, this place is quite informal, and serves up a seafood-intensive menu.

Wanna see a dudong, dude? Or maybe just a manatee? If you missed the deliberate omission just then, you don't deserve to go to the seldom-visited but sizeable isle of Koh Libong. Those who venture to this rubber-producing haven off the coast of Trang Province are invariably rewarded with free sightseeing trips to visit the endangered sea cows in captivity, courtesy of the generous resorts based here. Unusually for Andaman beaches, the sands here are dark yellow, rather than pearly white.

This island was once popular with marauding pirates. It also hosted a prison colony, before (horror upon horrors) it was used as the location for TV series Survivor: Thailand. Dark history and murky snorkelling conditions aside, there are clean beaches, plus hikes to cool waterfalls and dreamy lookout points. The island closes down during the monsoon season, giving monitor lizards, sea turtles, and crab-eating macaques free reign of the island.

They say love knows no bounds — and, buoy, they shore were right! Ever since a buoyant local couple fell in love while participating in a dive event — then got hitched in the drink, spawning an annual fad — Ko Kradan has been best known for hosting a gimmicky mass underwater-wedding ritual. This is a waste: the stunning, privately owned beach offers wide-screen views of scattered offshore islands, and a large, mostly intact coral reef. But the lack of decent accommodation means this tranquil spot is best visited on a daytrip.

This deceptively large island is best known for the raucous full-moon party on what was once its nicest beach, Had Rin, which has now, inevitably, been overdeveloped to cater to the backpacking hordes. Leave them to it. There are numerous brilliant strips in the quieter areas. Thong Nai Pan Noi, Bottle Beach and Haad Khom on the north coast deserve honourable mentions. Leela Beach is arguably the best of a good bunch, however, it occupies the western tip of the Had Rin peninsula and offers beach bods white sands, warm limpid waters and, until now, comparatively small-scale development.

Forget icing-sugar sands and warm turquoise waters: here's a shoreline that wasn't made for sunbathing. In fact, from afar, Shell Fossil Beach in Krabi looks like it's made from concrete slabs. This is actually a 75-million-year accumulation of shell deposits. This is a phenomenon that can only be seen at two other locations: one in Japan, the other in the US.