Mae Nam, Koh Samui
This beautiful stretch of creamy sand, on Koh Samui’s north coast, is one of the most gorgeous beaches on the island, so you’d expect it to be packed with tourists. Happily, the crowds tend to miss the tucked-away road turning, leaving plenty of sandy square-footage for those in the know. Spend the morning watching kitesurfers twisting in the wind, lunch on cold Chang beer and freshly-caught red snapper from a bamboo shack, and then sleep it off under a swaying coconut palm.
Twin with: A post-beach bevvy at W Retreat Koh Samui’s happening Woo Bar. Every Thursday is mojito night, with free-flowing rum cocktails from 6pm till midnight for THB1,300 (£27). Doubles from THB23,740 (£495), room only.
Pansea Beach, Phuket
This secret, coconut-lined cove on the northwest coast of Phuket is shared with the Surin Phuket and the terribly posh Amanpuri — but few visitors realise that it’s actually open to the public. The hotels want to keep it that way, so it’s tricky to reach but there’s a secret path between the two hotel entrances through the bamboo groves. Or you can catch a long-tail round from Surin or Bang Tao Beaches. Find your way here, and you’ll be greeted by a sweet band of sugary sand, bookended by smooth boulders, with bath-warm waters and a distinctly luxurious vibe.
Twin with: Sunset. They’re phenomenal here; the sun a maraschino cherry in a peach melba sky; the sea an expanse of molten gold. Sigh.
Bamboo Beach, Koh Lanta
It’s not the easiest beach to reach — you’re looking at a minimum five hours of travel on buses, boats and taxis from Phuket Airport — but once you sink your toes into that crystalline sand, it’ll all be worth it. One for those who like their beaches private, this petite seashore is a dreamy mix of warm, shallow waters and labyrinth-like rock pools teeming with candy-striped bannerfish, flouncy red lionfish and grumpy-looking groupers. Above land is just as impressive with it being backed by a national park. Look out for theatrical black-naped orioles, dinky chestnut-headed bee-eaters and racket-tailed drongos.
Twin with: Island-hopping from Krabi all the way down to Koh Lipe, on the border with Malaysia.
Ao Ta Khian, Koh Kood
A ravishing rural setting with not a jet ski, 7-Eleven or ATM in sight makes Koh Kood more than just a wee bit magical. Snuggled against the east coast of Thailand, this large, mountainous island is webbed with jungle lagoons, sparkling waterfalls, and the bluest seas and brightest beaches outside of the Maldives. Our favourite? The satin-soft sands of Ao Ta Khian, where you can sling your hammock between a couple of palms and fall asleep to the sound of the lapping Gulf of Siam, interspersed with the occasional cry of a cockerel or tinkling bell of a water buffalo.
Twin with: A marriage proposal or honeymoon at Soneva Kiri, where you can sleep in souped-up Robinson Crusoe-style villas and have Champagne delivered by zip-wire to tree-pod dining rooms. Pool suites from £715, room only.
Koh Munnork Private Island, Gulf of Siam
Bangkokians looking for a weekend break tend to escape to the well-worn beaches of Koh Chang or Koh Samet, but travel a bit further and you’ll hit Koh Munnork, a tranquil 18 acres of land blessed with aquamarine waters and silky silver bays. The privately-owned island is home to just one resort, the dully-named — and decorated — Mun Nork Island Resort, but you won’t be worried about the insipid sofa with those tumbling white sands right outside your front door.
Twin with: Nothing. The appeal of Munnork is that there’s virtually nothing to do. Now, lie back, read another book and order a coconut cocktail. Doubles from £115, B&B.
Read more in the September 2015 issue of National Geographic Traveller (UK)