Forget the crowds of Phuket. Thailand’s best-kept secrets float between Krabi and Trang provinces, all very close to each other in the Andaman Sea.
These seven islands form a stunning chain, yet most tourists have never heard of them.
From village life on Koh Mook to pristine reefs at Koh Rok, each island offers something unique.
This guide reveals what makes each one special, plus the best times to visit and smart island-hopping routes. Trust me, this will save you hours of planning. 😊
1. Koh Ngai
a. Why Visit
Koh Ngai is your escape from everything.
No roads, no villages, no motorbikes. Just you, the jungle, and some of the clearest water you’ll ever see.
It’s perfect if you want to completely disconnect and do absolutely nothing.
b. Key Highlights
- Main Beach (Long Beach): 2km of white sand with reef access right from shore
- Great Hornbills: These massive birds fly between resorts at sunrise
- Coral drop-off: Just 50-100 meters from the beach
c. Things to Do
- Snorkel the house reef: Walk straight into the water and swim to the drop-off. You’ll see parrotfish, moorish idols, and sometimes blacktip reef sharks
- Jungle hike to Paradise Beach: A30-minute sweaty trek through the forest leads to an empty beach on the south side
- Kayak the eastern coast: Paddle to hidden coves you can’t reach on foot
- Watch hornbills at breakfast: They’re most active early morning around Thapwarin Resort
2. Koh Mook
a. Why Visit
Koh Mook gives you the real island life experience.
It has a Muslim fishing village where you’ll eat street food next to locals, plus one of Thailand’s most famous natural wonders.
You get authentic culture and stunning nature in one spot.
b. Key Highlights
- Sivalai Beach: A perfect sandbar jutting into the ocean
- Emerald Cave: A hidden lagoon inside the island, accessed through a dark sea tunnel
- Charlie Beach: Dramatic sunset spot framed by limestone cliffs
- Local village: Real island life with schools, mosques, and fishing boats
c. Things to Do
- Swim through Emerald Cave early: Hire a longtail boat at 7:30 AM to beat the tour groups. Swimming through that dark tunnel into the hidden beach is magical when you’re alone
- Eat in the village: Try the Pad Thai at Mong Bar and passion fruit smoothies at Miss Island
- Trek to Sabai Beach: A rough jungle path leads to this secret beach on the west coast
- Watch for dugongs: Kayak the eastern mangroves where these sea cows sometimes feed
3. Koh Rok
a. Why Visit
Koh Rok has some of the clearest water in Thailand. The sand is powder-soft, and the coral is vibrant and full of life.
It’s strictly protected, so there are no resorts, just pure nature.
b. Key Highlights
- Twin islands: Koh Rok Nai and Koh Rok Nok separated by a coral-filled channel
- Ao Man Sai Beach: Blindingly white sand and neon turquoise water
- Monitor lizards: Huge prehistoric-looking lizards roam the beaches
- World-class snorkeling: Visibility often exceeds 20 meters
c. Things to Do
- Snorkel the channel: Drift between the two islands over massive coral formations
- Spot monitor lizards: These gentle giants hang around the ranger station
- Explore both islands: Each has different snorkeling spots and beaches
Season alert: Completely closed July 1 to September 30.
4. Koh Haa (Five Island)
a. Why Visit
Koh Haa is for serious water lovers.
These five limestone pinnacles offer some of Thailand’s best diving and snorkeling, with underwater caves, chimneys, and walls dropping into the deep blue.
b. Key Highlights
- The Lagoon: A natural swimming pool in the middle of the ocean
- The Cathedral: Massive underwater cave system where light creates magic
- The Chimney: A vertical swim-through from deep to shallow
- 30-meter visibility: Some of the clearest water in the Andaman
c. Things to Do
- Scuba dive the caves: The Cathedral and Chimney are bucket-list dive sites
- Snorkel the walls: Even from the surface, you can see deep-water fish
- Free dive the lagoon: Perfect for practicing in safe, clear water
- Photography: The light and water clarity create incredible underwater shots
Access note: No overnight stays possible.
5. Koh Kradan
a. Why Visit
Koh Kradan is Instagram paradise. It won “Best Beach in the World” awards for good reason.
The water is electric blue, the sand is perfect white, and at low tide, massive sandbars appear like magic.
b. Key Highlights
- Sunrise Beach (Koh Kradan Beach): The award-winning main beach facing east
- Sunset Beach: Quieter west coast beach for evening colors
- Walkable sandbars: At low tide, walk hundreds of meters into the sea
- Reef access from shore: Both north and south ends have great snorkeling
c. Things to Do
- Snorkel the north and south reefs: South has soft corals and fish schools, north has better visibility
- Walk the low tide sandbars: Best photo opportunities when the tide pulls back
- Trek to Sunset Beach: 15-minute jungle walk to the quiet western side
- Kayak the perimeter: Paddle around to find limestone formations and hidden spots
6. Koh Libong
a. Why Visit
Koh Libong is for nature enthusiasts. It’s not about perfect beaches here.
It’s about seeing dugongs, exploring rubber plantations, and experiencing a real Thai Muslim fishing community untouched by mass tourism.
b. Key Highlights
- Dugong population: Thailand’s largest group of sea cows lives here
- Stone Bridge: Natural rock arch on a secluded beach
- Batu Bute village: Traditional fishing village on stilts
c. Things to Do
- Spot dugongs from the tower: Climb the observation tower at Batu Bute for ethical viewing
- Hike to Point Dugong: Challenging trail with rope sections leads to caves and viewpoints
- Explore by scooter: Safe roads through rubber plantations and villages
- Eat at Fisherman’s Kitchen: Fresh, cheap seafood in an authentic setting
7. Koh Lanta
a. Why Visit
Koh Lanta is your perfect base camp. It has everything the tiny islands lack (hospital, ATMs, internet) but still feels laid-back and beautiful.
You can take day trips to the wilder islands but come back to comfort.
b. Key Highlights
- National Park: Lighthouse, hiking trails, and wild monkeys at the southern tip
- Long beaches: Miles of sunset-facing sand with beach bars
- Old Town: Historic Chinese-Thai village on stilts
c. Things to Do
- Visit Lanta Animal Welfare: Tour this amazing sanctuary that’s transformed the island’s stray situation
- Cook at Time for Lime: Thailand’s best cooking school, profits support the animal sanctuary
- Explore Old Town: Teak houses over water, local restaurants, and genuine heritage feel
- Scooter the east coast: Discover mangroves, rubber plantations, and hidden viewpoints
- Kayak Tung Yee Peng mangroves: Silent paddling through tunnels of green
Map of the 7 Islands
Recommended Itineraries
Option A: 4 Days
- Day 1-2: Koh Lanta
- Day 3: Koh Haa & Koh Rok (Join a Boat Tour from Koh Lanta)
- Day 4: Koh Ngai
Option B: 7 Days
- Day 1-2: Koh Lanta
- Day 3: Koh Haa & Koh Rok (Join a Boat Tour from Koh Lanta)
- Day 4-5: Koh Ngai
- Day 6-7: Koh Mook
Option C: 10 Days
- Day 1-2: Koh Lanta
- Day 3: Koh Haa & Koh Rok (Join a Boat Tour from Koh Lanta)
- Day 4-5: Koh Ngai
- Day 6: Koh Kradan
- Day 7-9: Koh Mook
- Day 10: Koh Libong
Best Time to Visit These 7 Islands
a. January to March: Peak Conditions
This is golden time. Calm seas, blue skies, temperatures around 28-32°C.
Every ferry runs, every island is open, but expect higher prices and more tourists. Still worth it for guaranteed perfect weather.
b. April: Hot but Calm Seas
Temperature hits 35-38°C. The sea stays calm, everything’s still open. Good if you handle heat well. Songkran festival (mid-April) brings Thai tourists.
c. May 1-15: Last Chance Window
The risky bargain period. Weather turns unpredictable, ferry schedules reduce.
You might get lucky with lower prices and fewer crowds, or you might hit early monsoon.
d. May 16 to October 14: Monsoon Season
Sea transport slows down, schedules become limited, and travel depends heavily on weather. Conditions often include heavy rainfall, rough seas, and gusty winds.
e. October 15 to November: Transition Season
The secret sweet spot. Everything’s green and fresh after the rains. Limited ferry schedules at first, but crowds haven’t arrived yet. Some November storms possible.
f. December: Great Weather Returns
Cool and dry with occasional rain. Full ferry schedules restart. Perfect balance before the Christmas rush. One of the best months overall.
