🔄 Updated 21 Jun 2026
If you're on Koh Phangan and want to escape the buzz of Haad Rin for a day, Than Sadet is a solid answer. It's on the east side of the island, inside Than Sadet-Koh Phangan National Park — a stream running 2–3 kilometres that drops in a series of small and large falls over big boulders before reaching the sea at Than Sadet Beach, a tiny, quiet beach that barely sees a crowd. One trip gets you the waterfall, a short jungle walk, and a finish at the sea.
The name "Than Sadet" comes from the Chakri kings who visited here across several reigns, especially King Rama V, who first came around 1888 and returned many more times throughout his reign. That's why there are rocks carved with the royal cipher along the stream that survive to this day. Locals on Koh Phangan have long regarded Than Sadet as a sacred place.
What Than Sadet is, and why it's worth the trip
Than Sadet isn't a single tall plunge waterfall like a lot of people picture. It's a stream that steps down over big boulders in several stages, with pools you can get into at multiple points — some calm enough to soak in, some with a small fall you can stand under for a shower. The draw is the shady jungle and the quiet, because far fewer people come here than to the busier falls near Thong Sala.
- The island's biggest waterfall — Than Sadet is the longest, largest waterfall stream on Koh Phangan, with several swimmable pools running up the stream.
- Royal cipher carvings — rocks carved with the royal cipher sit near where the stream meets the sea, evidence of the royal visits by King Rama V and the kings who followed.
- Beach in the same day — it's a short walk from the falls to Than Sadet Beach, so you can swim in the freshwater pools and then head straight into the sea.
- Genuinely quiet — because it's on the east coast and the access road is fairly far out, it's far less crowded than the island's most popular spots.
Want more out of Koh Phangan? Book tours & activities
Booking online ahead on Klook or GetYourGuide is usually cheaper than the gate and skips the queue. Pick only the experiences you actually want — prices and availability are shown live on each site.
The royal cipher rocks — the island's piece of history
This is what makes Than Sadet different from an ordinary waterfall. King Rama V visited Than Sadet from around 1888 and came back many times over his reign. Later, King Rama VI, King Rama VII, and King Rama IX also visited. So along the stream, near where the water flows out to the sea, there are boulders carved with the royal ciphers as a memorial. Walk up the stream just a short way from the beach and you'll see them.
Respect the site
The royal cipher rocks are antiquities and are revered by local people. You can look and take photos, but don't climb or step on them, don't scratch or write over the carvings, and dress modestly when you're in that area.
How to get to Than Sadet Waterfall
Than Sadet is on the east side of the island. The main entrance turns off the road near Baan Tai. These days there's a concrete road running alongside the stream, with parking and steps down to the swimmable pools, so it's much easier to reach than it used to be. But the final stretch of road into Than Sadet still has steep climbs and tight bends — take care if you're riding a motorbike yourself.
- Motorbike — the most freedom and the fastest way in, but the last stretch is steep with hairpin turns. If you're not confident riding up hills, don't push it — take it slow and check your brakes before you set off.
- Songthaew / island taxi — shared trucks from Thong Sala pier heading toward Thong Nai Pan often pass through and can drop you at Than Sadet. A shared ride runs around 300 THB per person; agree the fare before you get in.
- Longtail boat — at certain times there are boats from the Thong Nai Pan side or from Koh Samui into Than Sadet Beach, good if you want to avoid the steep road, but the schedule is limited and depends on the swell.
- Distance from Thong Sala — about 30–40 min by motorbike from Thong Sala; leave extra time for the climb up the hill.
Entry fee, opening hours, and the best water season
Than Sadet sits inside a national park, so there's the usual park entry fee and set opening and closing hours. Go during the day and leave time to head back before evening.
- Park entry fee — around 100 THB per adult (foreigner rate); kids usually enter free. This covers the beach and the lower falls.
- Opening hours — generally around 08:00–16:00. Go before early afternoon so you have time to swim and walk back at an easy pace.
- High-water season — the falls look best and the water's fullest after the rains, roughly late year into early year (November–February). In the mid-year dry months the water can drop, but you can still swim in the pools.
- Weekdays — come on a weekday and there are even fewer people, so you get the quiet to yourself. Avoid long holiday weekends if you want a private pool.
A short jungle walk + swimming the falls
The charm of Than Sadet is that you can walk the jungle without wearing yourself out. A trail follows the stream, climbing over the big boulders and past several pools — the higher up toward the source you go, the deeper and quieter the pools get, good if you want to soak in peace. Along the way you pass hibiscus bushes, coconut palms, and banana trees, shaded the whole time. If you like a longer walk, there's a trail that continues to Thong Nai Pan beach, about an hour away.
- Swimming the falls — the lower pools near the car park are the easiest to get into and good for families; the deeper pools you can soak in are further up the stream.
- The river mouth at the sea — where the freshwater stream flows out to the sea is an easy spot to rinse off after a salt-water swim, and it's a nice photo spot too.
- Walk on to nearby beaches — Haad Thong Reng is about a 5-min walk away, and a jungle trail continues to Thong Nai Pan beach in about 1 hour.
- Wildlife — there are monkeys and other wildlife in the park, so don't feed the monkeys and keep your food packed away.
Stay safe on the walk and in the water
The rocks along the falls are very slippery, especially after rain. Wear shoes with grip, don't walk on wet rock barefoot, and check the water level before getting in. If it rains hard, the water upstream can come down fast — get out of the pool right away — and never jump into a pool where you can't see the bottom.
Than Sadet Beach — finishing the day at a quiet sea
After the falls, a few steps gets you to Than Sadet Beach — a curved stretch of sand about 300 metres long, flanked by the freshwater stream, with clear water and few people. It's a good place to rest after the walk. There are a few small local restaurants and guesthouses along the beach, but it never gets crowded. It's the opposite end of the spectrum from Haad Rin.
Than Sadet Beach
A white-sand beach about 300 metres long, clear and quiet, with a freshwater stream to rinse off in — good for resting after swimming the falls.
Haad Thong Reng
A smaller, quieter beach about a 5-min walk from Than Sadet Beach. Very few people — good for finding a calm corner.
Thong Nai Pan
A popular beach on the northeast side. Hike on from Than Sadet for about 1 hour, or drive around to reach it.
What to bring and what to watch out for
- Cash — bring cash for the entry fee and transport. There's no convenient ATM on this side of the island like there is in Thong Sala.
- Shoes you can walk in — wear trainers or rubber shoes that can handle water and rock walking; skip slippery flip-flops.
- Sun protection + water — the jungle is shaded, but the beach and parking area get strong sun, so carry water and sunscreen.
- Pack out your rubbish — this is a national park and a sacred site, so take every piece of rubbish back with you and don't drop anything in the stream.
- Check the weather — during the late-year monsoon it rains hard, the steep road gets slippery, and boats may stop running. Check before you head out.
Being straight about the steep road
The road into Than Sadet has steep climbs that a beginner on a motorbike may not handle. If you're not confident, take a songthaew or island taxi rather than risk a fall. Wear a helmet every time, and don't ride when it's raining and the road is wet.
Plan a full Koh Phangan trip — beaches, waterfalls, and viewpoints
See the Koh Phangan travel guide →