Everybody knows Thailand’s headline islands—Phi Phi, Phuket, and Koh Pha-ngan—and they’re famous for a reason. But if you’ve ever dreamed of powdery sand without the shoulder-to-shoulder beach chairs, Thailand still has plenty of places where the vibe is calmer, the water is clearer, and the sunsets feel like your own private show.
Below are six lesser-known(ish) islands and island groups that deliver that “I can’t believe this is real” feeling—Similan, Koh Tao, Koh Lipe, the Khai Islands, Koh Phayam, and Koh Mak—with practical tips on who each one is best for, what to do, and how to plan around seasonal closures and ferry schedules.
Quick pick: which island fits your travel style?
| Island | Best for | Vibe | Ideal trip length |
|---|---|---|---|
| Similan Islands | World-class snorkeling/diving | Protected national park, pristine, day-trip or liveaboard | Day trip (or 2–4 days liveaboard) |
| Koh Tao | Diving certifications + beach time | Social but not “mega-party,” compact and easy | 3–5 days |
| Koh Lipe | Beautiful beaches + snorkeling from shore | Small, walkable, “tropical postcard” | 3–6 days |
| Khai Islands (Phuket) | Quick half-day beach escape | Tiny sandbar islands, easy boat day trip | Half-day or day trip |
| Koh Phayam | Quiet, low-key, off-grid-lite | Barefoot, artsy, slow living | 2–5 days |
| Koh Mak | Cycling + calm beaches | Peaceful, family-friendly, low nightlife | 3–6 days |
1) Similan Islands: Thailand’s “pinch-me” water (with important seasonal timing)
If your happy place is neon-blue water, giant granite boulders, and snorkeling that looks like a screensaver, the Similan Islands are the dream. This island chain sits off Thailand’s Andaman coast and is protected as Mu Ko Similan National Park, which helps keep the reefs and beaches spectacular.
What to know before you go (the big one: closures)
The Similan Islands are seasonally closed every year for ecosystem recovery and monsoon conditions. For example, the park announced closure May 16 to October 14, 2025, with reopening October 15, 2025. Dates can vary slightly year to year, so always check the latest park notice when planning.
Also, Thailand has been rolling out e-ticketing for select marine parks, including Similan, which can affect how you enter (often through tour operators or official channels).
Best things to do
- Snorkel straight from the beach on calm days (visibility can be unreal).
- Dive for dramatic rock formations and vibrant reef life.
- Hike to viewpoints for that iconic boulder-and-bay panorama.
Getting there (typical logistics)
Most visitors go by speedboat from the Khao Lak/Thap Lamu area, with crossings commonly around 1–1.5 hours depending on sea conditions and operator. Phuket Tickets
Who it’s best for
- Snorkelers and divers who want a national-park-level “wow.”
- Travelers happy with a structured day trip (or a dive liveaboard) rather than DIY island wandering.
2) Koh Tao: small island, big underwater adventures
Koh Tao sits in the Gulf of Thailand (north of Koh Phangan and Koh Samui) and has built a global reputation as a fantastic place to learn to dive or rack up fun dives without breaking the budget. It’s compact, easy to navigate, and packed with viewpoints, coves, and snorkel spots.
Best things to do
- Get your PADI/Open Water (or continue with Advanced)—there are tons of schools and daily trips.
- Snorkel in sheltered bays on calm days.
- Catch sunset from a viewpoint, then grab a casual dinner in town.
Practical tips (the “do this and your trip is smoother” list)
- Choose well-reviewed dive operators, and don’t be shy about asking about group sizes, safety briefings, and equipment maintenance.
- If you’re sensitive to noise, pick lodging away from the main bar strips so you can sleep like a champion.
Who it’s best for
- First-time divers, diver couples, solo travelers who want a social-but-not-overwhelming island base.
- Anyone who likes the idea of beach time + activity (you can do both without long travel days).
3) Koh Lipe: tiny, walkable, and wildly pretty
Koh Lipe is one of those islands that converts people into “I’ll come back every year” types. It’s in southern Thailand and is part of the Tarutao National Marine Park (Adang–Rawi group), which helps protect the surrounding marine life. Thai National Parks
Beaches you’ll actually use
Koh Lipe’s main beaches are easy to reach, and they each have a distinct mood:
- Sunrise Beach: morning light, calm water days, great for early swims
- Sunset Beach: quieter feel, dreamy evening colors
- Pattaya Beach: convenient and lively (and yes—it’s nothing like Pattaya city)
Walking Street (and the one thing to watch for)
The island’s central strip—often called Walking Street—is where you’ll find food, shops, dive operators, and little cafes. It’s walkable, but you may still see motorbike sidecars or small service vehicles, so just stay aware, especially at night.
Getting to Koh Lipe (most common route)
A classic approach is:
- Fly into Hat Yai (or arrive overland),
- Transfer to Pak Bara Pier,
- Take a boat to Koh Lipe.
Pak Bara routes are widely advertised as running year-round, though schedules can be reduced in the low/monsoon season. Koh Lipe Island
If you’re coming via Malaysia (Langkawi), note that direct services can be seasonal due to monsoon conditions—plan this route carefully. Ferry Lipe
Who it’s best for
- Beach lovers who want beauty + convenience (you can walk almost everywhere).
- Snorkelers who love easy access to coral and fish.
4) Khai Islands: the easiest “wow” day trip from Phuket
If you’re staying in Phuket and want turquoise water without a long travel day, the Khai Islands are a classic half-day or day-trip pick. They’re tiny islands with bright water, soft sand, and quick boat access—often around 15–30 minutes by speedboat depending on departure point and conditions.
You’ll typically see the trio marketed as Khai Nok / Khai Nai / Khai Nui on major tour platforms, which suggests these trips are actively running and bookable.
What to expect
- No big hotels—this is about beach time and swimming.
- A few simple snack/drink stalls (availability varies by season and operator).
- Short, sweet snorkeling stops when the sea is calm.
Who it’s best for
- Anyone who wants an island fix while based in Phuket.
- Families and groups who like low-effort, high-reward outings.
5) Koh Phayam: barefoot calm, no cars, and slow days done right
Koh Phayam (near Ranong) is a favorite for travelers who want Thailand to feel simpler, quieter, and a little artsy. It’s widely described as car-free, which makes the whole island feel gentler—more walking, more bicycles, more breezy scooter rides, fewer honking streets. Travelers & Dreamers
Best things to do
- Long Beach (Ao Yai) for wide-open sand and mellow swims
- Quiet beach-hopping (bring water and snacks and just roam)
- Sunset sessions where the soundtrack is basically “waves + happy sighs”
A quick expectations check
- Accommodations lean simple and cozy rather than luxury mega-resorts.
- Wi-Fi can be available, but it’s not the island’s main love language.
Who it’s best for
- Travelers who want tranquility more than nightlife.
- Anyone craving the “read a book, swim, nap, repeat” rhythm.
6) Koh Mak: cycling, calm water, and “why isn’t everyone here?”
Koh Mak is a soft-spoken gem in eastern Thailand—more about quiet beaches, family-friendly swims, and exploring by bicycle than late-night parties. It’s often recommended for travelers who want a relaxing base that still has enough cafes and comforts to feel easy.
What to plan for (money + logistics)
ATM availability is commonly described as limited and sometimes unreliable, so it’s smart to arrive with enough cash for rentals, small meals, and local transport—even if your resort accepts cards. Koh Chang Island Travel Guide
Best things to do
- Bike the island (flat-ish roads + short distances = perfect)
- Beach-hop between calm bays
- Take a boat day trip to nearby small islands/reefs when conditions are good
Who it’s best for
- Couples, families, and anyone who wants peace + gentle adventure.
- Travelers who love a destination that feels uncrowded even in high season.
The bottom line: the “hidden island” dream is still real
Thailand’s famous islands can be incredible—especially early mornings and shoulder seasons—but if you’re chasing that quieter paradise feeling, these six spots deliver in different ways:
- Want the clearest water and best snorkeling wow-factor? Start with Similan (in season).
- Want diving + island ease? Koh Tao.
- Want walkable beaches and postcard scenery? Koh Lipe.
- Want the quickest island day trip from a busy base? Khai Islands.
- Want slow, mellow, car-free calm? Koh Phayam.
- Want cycling + relaxed beaches? Koh Mak.
And here’s the best secret of all: even on popular islands, you can still find peace by going early, walking 10 minutes farther, or choosing the “wrong” beach at the “right” time (sunrise swimmers know what’s up).
FAQ
What is the best lesser-known island in Thailand?
It depends on your style. Similan is the standout for snorkeling/diving (in season), while Koh Mak and Koh Phayam are favorites for quiet, uncrowded beach days.
How do you reach Thailand’s smaller islands?
Most islands are accessed by ferry or speedboat. Speedboats are faster and often pricier; ferries are usually cheaper and slower. For Koh Lipe specifically, routes from Pak Bara Pier are widely listed as operating year-round (with fewer trips in low season). Koh Lipe Island
Are the Similan Islands open year-round?
No—Similan is a protected national park with seasonal closures (commonly May–October). For example, officials announced a closure from May 16 to October 14, 2025, reopening October 15, 2025. Always confirm the current season dates before booking.
Can I still book Khai Islands trips from Phuket?
Yes—Khai island day trips remain widely listed on major tour platforms, which is a good sign they’re actively running.