The picturesque islands that lie scattered across the turquoise waters of the Gulf of Thailand are some of Cambodia‘s last pristine spots. None have paved roads, cash machines or 24-hour electricity, but what the islands lack in amenities they more than make up for in natural beauty. Unfortunately, development is just around the corner, so you will have to move fast to get there before the laid-back atmosphere is destroyed by an influx of planned luxury resorts.

Located two and a half hours from the mainland, the island of Koh Rong is stunning, with picture-perfect white sand beaches and placid aquamarine surf. The 78sqkm island, home to 43km of beaches, is packed with diving, snorkelling and jungle trekking opportunities. The most developed of the islands off port city Sihanoukville‘s shore, Koh Rong has more than a dozen guesthouses and bungalows, and small local restaurants serve cold beer and freshly caught seafood. The popular Monkey Island bar stays open late and has fire-dance performances every night. Paradise Bungalows, next door, offers accommodation with a laid-back vibe and a remarkably good wine selection at their bar. However, you can still find tranquil solitude in the many other parts of the island that remain almost completely untouched by development.

To the south of Koh Rong sits the island’s smaller, quieter sister, Koh Rong Samloem, dotted with beautiful, nearly empty beaches. The Dive Shop runs a boat between the two islands and has recently opened Robinson’s Bungalows – simple, inexpensive wooden cottages nestled in the jungle next to a windswept beach where the sunset paints each evening in vivid pinks and purples. In the next bay over is Lazy Beach, the island’s oldest resort and a perennial favourite. Its private beach, plentiful hammocks and full cocktail menu make it the perfect spot to laze away a weekend.

Off the shore of Ream National Park sits Koh Thmei, an almost uninhabited island flanked by mangrove forests. Koh Thmei Resort is the only place to stay on the island, and its peaceful, ecologically minded set up is perfect if you are looking to unwind. Solar power means the bungalows have electricity almost all day – a rarity on the islands – although there is no reason to spend much time indoors when there are beaches littered with exotic shells, a coral reef ripe for snorkelling and more than a hundred species of rare birds to observe.

Closer to Sihanoukville is Koh ta Kiev, a small island just an hour offshore with rustic accommodation and camping options. Ten 103 Treehouse Bay has simple treehouses in the jungle, which makes their homemade bread, fresh pasta and other gourmet fare all the more unexpected. Down the beach, Crusoe Island offers inexpensive beachside camping and activities such as spear fishing, squid fishing and jungle treks.

Further north is the tiny island of Koh Totang, where Nomads Land, a collection of simple, ecologically friendly bungalows, offers sunset cruises, organic meals and hammocks best situated to savour the view of the spectacular blue-green waters.

Although none of these islands are more than three hours from the mainland, island-hopping off Cambodia’s coast can require patience – getting from one to the other may require going back to shore or hiring a private boat for the journey. But it is worth the effort to see some of Cambodia’s most gorgeous, untouched spots before they disappear forever.

The article 'Island-hopping off Cambodia’s coast' was published in partnership with Lonely Planet.