The Thailand Islands That Still Feel Like a Secret

A different kind of Thailand

Beyond the postcards

Thailand's islands have a reputation. Crystal water. White sand. Palm trees swaying in the breeze. But in recent years many have become victims of their own beauty — packed with day-trippers, loud music and rows of beach chairs where there used to be nothing but tide lines.

The islands in this guide are different. They still offer that impossible turquoise water and soft sand, but they have held on to something rarer: peace. These are places where you hear the waves at night instead of bass from the beach bar, where local fishermen still outnumber tourists, and where the late-afternoon light hits the water just right and you feel like you have found something the guidebooks missed.

Eastern Gulf

Koh Kood

The island that time almost forgot.

Koh Kood (also spelt Ko Kut) sits in the far eastern Gulf of Thailand, in Trat province, almost against the Cambodian maritime border — about as far from Bangkok as a Thai island gets. It's the country's fourth-largest island, yet one of its least developed: there's no airport and no car ferry, so you arrive by speedboat or catamaran from Laem Sok pier near Trat, roughly an hour across open water.

The climate is classic tropical Gulf. The dry high season runs from about November to April, when the sea flattens, the water turns glassy and the late-afternoon light does its thing. The southwest monsoon (May to October) brings rain and rougher water, and many of the smaller resorts and boat operators wind down or close — so December to March is the sweet spot.

Where to go: Klong Chao is the island's showpiece beach, a long curve of pale sand lined with longtails, with the Klong Chao waterfall a short kayak-and-walk inland. Ao Tapao and Ao Phrao offer quieter sand and fine sunsets, while Bang Bao in the south has a gentle reef for snorkelling straight off the beach. Between them lies thick jungle laced with streams and mangrove.

Best for: slow travel, couples, waterfalls and hammocks.

Aerial view of a Koh Kood bay with turquoise water and moored boats — Late light over Koh Kood's hidden bays

Koh Kood beach with longtail boats and lush jungle behind — The Klong Chao area — one of the island's finest corners

Serene Koh Kood beach with longtail boats and calm shallows — The kind of beach where hours quietly disappear

Andaman Sea

Koh Lipe

The "Maldives of Thailand" that still feels human.

Koh Lipe lies at the opposite end of the country — the deep south of the Andaman Sea, in Satun province, closer to Malaysia's Langkawi than to Phuket. It sits on the edge of Tarutao National Marine Park, a protected archipelago of jungle-covered islands, reached by speedboat or ferry from Pak Bara pier (about 90 minutes) or seasonally direct from Langkawi.

This is Andaman weather, so the rhythm matches the west coast: November to April is the dry, calm high season with the clearest water and best visibility, while the monsoon from mid-May to mid-October brings big swells and restricted national-park boat access. Aim for December to March.

The island is tiny and walkable, shaped by three beaches. Sunrise Beach (Hat Chao Ley) is the long, quiet stretch of squeaky white sand on the east; Sunset Beach is the smallest and most low-key; and Pattaya Beach on the south holds the main pier and the buzz. Between them runs Walking Street, a lane of seafood grills and bars that comes alive after dark.

The real magic is just offshore. Longtail day trips run to Koh Adang, Koh Rawi and the red-pebble beach of Koh Hin Ngam, where the snorkelling over coral gardens is superb — a village to eat and drink in, with empty islands a five-minute boat ride away.

Aerial of the Koh Lipe sandbar between two beaches with resorts and boats — The sandbar between Pattaya and Sunrise Beach

Koh Lipe shoreline with village and longtail boats — Vibrant but relaxed — Koh Lipe's shoreline

Koh Lipe beach aerial at sunset with clear Andaman water — Sunset light on the clear Andaman shallows

Trang Archipelago

Koh Kradan & Koh Mook

Where the Andaman still feels wild.

Both islands lie off Trang province on the southern Andaman coast, within Hat Chao Mai National Park, reached by longtail or speedboat from the Trang mainland piers. Like the rest of the Andaman they're at their best from November to April, when the sea is calm and the water clear; the southwest monsoon (May to October) closes much of the coast down.

Koh Kradan

Koh Kradan is, for many people, simply the most beautiful beach in Thailand — in 2023 it was named the world's best beach by the World Beach Guide. The island is little more than a long, west-facing ribbon of powder-soft sand backed by thick jungle, with a shallow coral reef just offshore that you can snorkel straight from the sand. Development is minimal: a scatter of low-key resorts, no real roads, and days that revolve around swimming, drifting over the reef and watching the sun sink into the Andaman. It's also famous for the underwater wedding ceremony held here every Valentine's Day. The water is clearest from December to March, and by day's end the whole beach turns gold. Come for the snorkelling and the sunsets — and for how gloriously little there is to do.

Koh Mook

Koh Mook (Koh Muk) is best known for one unforgettable trick: the Emerald Cave, or Tham Morakot. From the sea you swim through an 80-metre pitch-dark tunnel in the limestone and emerge into a hidden hong — a collapsed cavern open to the sky, ringed by jungle walls and a tiny beach that smugglers once used to stash cargo. Go early, before the day-trip boats arrive and ideally at lower tide. Beyond the cave the island has a very different character to Kradan: a working Muslim fishing village on the east side, rubber plantations inland, and the long, quiet Charlie Beach (Hat Farang) on the west, with good snorkelling at its southern end. It makes an easy, characterful base for exploring the wider Trang archipelago by longtail.

Krabi & Phang Nga

Dramatic Limestone & Hidden Lagoons

The islands around Krabi deliver some of Thailand's most cinematic landscapes.

The islands scattered off Krabi and neighbouring Phang Nga province, on Thailand's Andaman coast, are the postcard everyone pictures: sheer limestone karsts rising straight out of jade-green water, hidden lagoons and caves reachable only by boat. The mainland gateways are Ao Nang and Krabi Town, with Phuket and Phang Nga Bay just to the west — most island-hopping is done by longtail or speedboat on day trips. The seasons follow the Andaman pattern: November to April is dry, calm and clear, while the May-to-October monsoon can make the open crossings rough. Aim for the cool, dry months of December to February.

The highlights are many. Koh Hong (Krabi) is a favourite — a horseshoe of cliffs enclosing a still, turquoise lagoon made for kayaking. The Hong Island group and the beaches around Railay and Phra Nang deliver the same drama with powder sand. In Phang Nga Bay you'll find the famous James Bond Island (Koh Tapu) and a maze of mangrove-lined hongs best explored by sea kayak. For something slower, Koh Yao Noi and Koh Yao Yai sit quietly between Krabi and Phuket — rural, Muslim-majority islands with rice paddies, rubber trees and almost no nightlife, ideal for cycling. And the tiny Koh Khai islets make an easy snorkelling stop, their shallows thick with fish.

Koh Hong dramatic limestone cliffs enclosing a turquoise lagoon — Koh Hong — among the most spectacular spots near Krabi

Small island near Krabi ringed by turquoise water — Koh Khai and its neighbours — made for day trips

Koh Yao Noi beach in warm late-afternoon light — Koh Yao Noi — slower pace, incredible views

Gulf of Thailand

Koh Tao

The diver's island that still surprises.

Koh Tao — "Turtle Island" — sits in the western Gulf of Thailand, the northernmost of the Chumphon Archipelago, a short hop north of Koh Phangan and Koh Samui in Surat Thani province. You reach it by ferry from Chumphon on the mainland (around 1.5 to 2 hours) or up from Samui and Phangan.

Crucially, its weather runs on the Gulf calendar, almost the opposite of the Andaman islands: the driest, calmest stretch is roughly February to September, with superb diving visibility from March to August, while the northeast monsoon brings the heaviest rain from October to December. So when the west coast is washed out in low season, Koh Tao is often still glorious.

It's one of the cheapest and most popular places on earth to learn to dive, and the underwater sites are the main event — Chumphon Pinnacle, the whale-shark magnet of Sail Rock (shared with Phangan), the Japanese Gardens, and Shark Bay, where blacktip reef sharks patrol the shallows. Above water, Sairee Beach is the long, sociable west-coast strip for sunsets and dinner, while Tanote Bay and Freedom Beach are quieter and better for snorkelling. Hike up to the John-Suwan viewpoint for the classic twin-bay panorama, and don't miss Koh Nang Yuan just offshore — three islets joined by a single sandbar, one of the most photographed sights in the Gulf.

Aerial of Koh Tao's rugged coastline and bays at golden hour — Koh Tao's dramatic coastline in late light

Quiet Koh Tao beach with palm trees and a longtail boat — One of Koh Tao's many quiet beaches

Overview of Koh Tao's twin bays and surrounding reefs — The island's famous twin bays and reefs

Planning your trip

Best time to visit

November to April brings the most reliable weather across most of these islands. The Andaman side — Lipe, Kradan and Mook — is particularly beautiful in this window.

Getting around

Longtail boats remain the soul of island transport. For hopping between islands, speedboats and catamarans are reliable and scenic. Most islands are best explored on foot or by scooter.

Mapping a longer route around the kingdom? Our ThaiTripPlanner builds a day-by-day itinerary, and ThaiHolidayBudget helps you cost it realistically.