TL;DR: Sai Yok National Park is a 958km² park about 100km northwest of Kanchanaburi town, best known for the Sai Yok Yai waterfall that tumbles straight into the Kwai Noi river, its limestone caves and its floating raft-house accommodation. Foreign adults pay ฿300 (US$9) to enter and children ฿150 (US$4.50), with the park open 8am-4:30pm daily. Inside are Daowadueng Cave (about 240m), Lawa Cave (a large system reached by boat) and Khang Khao Cave, whose name means ‘bat cave’ and which is a habitat of Kitti’s hog-nosed bat, the world’s smallest mammal at around 2 grams. Do not confuse the park’s Sai Yok Yai falls with Sai Yok Noi, a separate, more accessible waterfall near Nam Tok station closer to town. Camping costs ฿30 (US$0.90) per person per night, tents rent from about ฿225 (US$6.80), and raft houses on the river are the signature stay. All prices ฿33 = US$1 (July 2026).
Sai Yok National Park is one of Kanchanaburi’s biggest and least rushed nature escapes, a 958km² stretch of forest, limestone hills and river far up Highway 323 from town. It is best known for a waterfall that falls directly into the river, for its caves, and for the floating raft houses that make an overnight here genuinely memorable. It is also the source of a lot of online confusion, because there are two “Sai Yok” waterfalls and only one is inside this park. This guide sorts that out and covers the entry fee, the caves, the raft houses, and how to actually get there.
Every price and figure below is checked against 2026 park and tourism sources, listed at the end.
Quick facts
| Detail | Info |
|---|---|
| Park area | 958km² |
| Entry fee (foreign adult) | ฿300 (US$9) |
| Entry fee (foreign child, 3-14) | ฿150 (US$4.50) |
| Entry fee (Thai adult / child) | ฿60 / ฿30 (US$1.80 / US$0.90) |
| Park hours | 8am-4:30pm daily |
| Distance from Kanchanaburi town | ~100km via Highway 323 |
| Camping | ฿30 (US$0.90) per person/night; tents from ~฿225 (US$6.80) |
| Bungalows | ~฿800-3,000 (US$24-91) |
| Signature stay | Floating raft houses on the Kwai Noi river |
Conversions at ฿33 = US$1 (July 2026).
Sai Yok Yai vs Sai Yok Noi: clearing up the confusion
The single most confused point about Sai Yok is that there are two waterfalls with similar names, and only Sai Yok Yai is inside the national park. Sai Yok Yai (‘big Sai Yok’) is the park’s headline waterfall, about 100km from Kanchanaburi town, and it is unusual because it drops directly into the Kwai Noi river next to the visitor centre and a suspension bridge, rather than into a pool you can swim in. Sai Yok Lek is a smaller fall about 300 metres downstream. Sai Yok Noi (‘little Sai Yok’) is a completely separate waterfall, closer to town near Nam Tok railway station, outside the park boundary and easy to reach as a free roadside stop.
| Feature | Sai Yok Yai | Sai Yok Noi |
|---|---|---|
| Location | Inside Sai Yok National Park, ~100km from town | Outside the park, near Nam Tok station, closer to town |
| Falls into | The Kwai Noi river | Roadside pools |
| Access | Longer trip up Highway 323 | Easy roadside stop, near the Death Railway terminus |
| Entry | Park fee ฿300 (US$9) foreign adult | Generally free |
If you are planning a proper day in the national park, you want Sai Yok Yai. If you just want an accessible waterfall while exploring the Death Railway end of the line, Sai Yok Noi near Nam Tok is the easier target.
The waterfalls and the river
Sai Yok Yai is the reason to come into the park, a waterfall that falls straight into the Kwai Noi river beside the visitor centre. It is not a big swimming waterfall like Erawan; the appeal is the setting, the suspension bridge, and the river itself running through the forest. The Kwai Noi is the park’s spine, and much of what makes Sai Yok special happens on or beside the water, from the raft houses to the boat access for some of the caves. Boat trips along the river are part of the experience for many visitors, so ask locally about current options when you arrive.
For a waterfall you can properly swim in with multiple tiers, the closer Erawan Waterfall is the better-known choice; Sai Yok is more about the river-and-forest atmosphere than a day of pool-hopping.
The caves, including the genuine bat cave
Sai Yok’s limestone hills hold several caves, and one of them, Khang Khao Cave, is a real ‘bat cave’ that is home to Kitti’s hog-nosed bat, the world’s smallest mammal. The main caves are Daowadueng Cave, around 240 metres long and known for its formations, and Lawa Cave, a larger system usually reached by boat along the river. Khang Khao Cave takes its name from the Thai word for bat, and it is associated with Kitti’s hog-nosed bat (the bumblebee bat), which weighs around 2 grams with a body just 2.5-3cm long, a species tied to the limestone caves of this part of Kanchanaburi.
One honest clarification worth making: the famous evening spectacle of millions of bats streaming out of a cave that many travellers have in mind is at Khao Chong Pran in Ratchaburi province, a different site with a different, far more numerous species. That is not inside Sai Yok National Park. Sai Yok’s bat connection is the rare, tiny hog-nosed bat in its limestone caves, not a mass bat-flight show.
Cave access varies with season, river levels and staffing, and some caves need a boat or a guide, so check at the visitor centre on the day, bring a torch and wear shoes with grip.
Raft houses and staying overnight
Floating raft houses on the Kwai Noi river are Sai Yok’s signature stay, and they are the main reason to make it an overnight rather than a day trip. These range from simple park-run rafts to private raft resorts, and the appeal is waking up on the water with forest on all sides and little else around. Given the 100km distance from town, an overnight makes the long journey feel worthwhile in a way a rushed day trip does not.
If you would rather not stay on the water, the park also has bungalows ranging roughly ฿800-3,000 (US$24-91) and a campground where camping costs ฿30 (US$0.90) per person per night, with tents rentable from about ฿225 (US$6.80) so you need not carry your own. Book raft houses and bungalows ahead, especially at weekends and on Thai public holidays, since the popular ones fill up and the park’s own online booking can be unreliable.
Getting to Sai Yok National Park
The park entrance is about 100km northwest of Kanchanaburi town along Highway 323, roughly a 1.5-2 hour drive, with a final stretch of around 3km from the highway to the visitor centre. Public buses heading up the 323 toward Thong Pha Phum and Sangkhlaburi pass the turn-off, from where a motorcycle taxi covers the last few kilometres to the visitor centre. It is doable on public transport, but the distance and the need to link up a bus and a motorcycle taxi make a rented car, a hired taxi for the day, or an organised tour the more comfortable choice.
The closer Sai Yok Noi waterfall, by contrast, sits near Nam Tok station at the end of the Death Railway line and is far easier to reach, which is part of why the two get conflated. If your time is limited, our Kanchanaburi day trip guide and things to do in Kanchanaburi guide can help you decide whether Sai Yok is worth the longer haul or whether a closer sight fits better.
Honest downsides
Sai Yok is rewarding but it is not the easy win some visitors expect.
- It is far. At about 100km from town each way, this is a long trip for a day, and it works far better as an overnight.
- Sai Yok Yai is not a swimming waterfall. It falls into the river rather than a plunge pool, so if you came for a Erawan-style swim you may be underwhelmed.
- The name confusion trips people up. Plenty of visitors arrive at Sai Yok Noi near town thinking it is the national park, or vice versa; know which one you actually want.
- Cave access is not guaranteed. Season, water levels and staffing affect whether caves are open or reachable, so treat any specific cave as a maybe until you confirm on site.
- Public transport is fiddly. Reaching the park by bus plus motorcycle taxi is possible but slow, so a car or tour saves real hassle.
Planning the rest of your trip
If Sai Yok is on your list, check what’s on in Kanchanaburi for anything happening the same week, and weigh it against the province’s other big draws. For WWII history, the Bridge over the River Kwai and the Death Railway sit at the accessible end of the province, while Sai Yok is the remote nature option further out. Most visitors pick one nature park per trip rather than trying to cram Sai Yok and Erawan into the same short visit.
Sources
- Thai National Parks: Sai Yok National Park: park area (958km²), entry fees and hours, Sai Yok Yai and Sai Yok Lek waterfalls, caves (Daowadueng, Lawa, Khang Khao), Kitti’s hog-nosed bat, camping and bungalow prices, getting there
- Tourism Thailand: Sai Yok National Park: overview of the park, waterfalls, caves and river
- Tourism Thailand: Sai Yok Noi Waterfall: Sai Yok Noi as a separate waterfall near Nam Tok, distinct from the park’s Sai Yok Yai
- Tripadvisor: Sai Yok Yai Waterfall: the falls dropping into the Kwai Noi river, visitor practicalities
- The Lost Passport: Saiyok raft house escape: raft-house accommodation on the Kwai Noi river
- The Lost Passport / Tripadvisor: Sai Yok National Park reviews 2026: current visitor reviews, access and conditions