🔄 Updated 21 Jun 2026
If you've ever seen a photo of a waterfall where the water doesn't fall in one stream but pours down across a wide cliff like a curtain, with mist drifting up and catching a soft rainbow in the light — that's Chet Si Waterfall. It sits inside Phu Wua Wildlife Sanctuary, in Ban Tong subdistrict, Seka district, Bueng Kan province. Its real original name is Ka-am Waterfall, after the Ka-am stream that feeds it, while the name Chet Si ("seven colors") comes from the way the spray meets the sunlight and splits into many colors.
What sets this waterfall apart from most is its wide, gently sloping cliff, which spreads the water out over a broad area instead of funneling it into a single stream. When the water is full in the rainy season you see a white sheet covering the whole cliff face, with a rock terrace below where you can wade in. A lot of people describe it as a natural water park in the middle of the forest, because there are shallow pools to soak in and stretches where the water slides over the rock like a natural slide.
What is Chet Si Waterfall, and why "seven colors"?
Chet Si Waterfall is formed by the waters of the Ka-am stream, which flow down the sandstone cliffs of the Phu Wua range. There are four tiers in all, but none of them is the steep, plunging kind you get on a mountain — instead each is a wide sloping cliff where the water spreads across in a long sheet. As the water strikes the rock below it throws up a fine mist, and when the sun passes through that mist at just the right angle it refracts into different colors, which is how it got the name "seven colors."
Straight talk about the rainbow
That rainbow isn't visible as a clear seven colors all the time the way it looks in the promo shots. It depends on the angle of the sun and how much spray there is. The clearest window is from mid-morning to midday on a sunny day when the water is running strong. Come on an overcast day or when the water is low and you'll get a lovely wide cliff waterfall more than a striking rainbow.
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The rainy season is the best time — but be careful
Chet Si Waterfall is one that depends entirely on the rain. The water is full and runs strong from the rainy season into early cool season, roughly July to November. That's when the water spreads across the whole cliff as a wide white sheet, the mist drifts up, and your chances of seeing the rainbow are highest — and there's plenty of water on the rock terrace below to swim in. This really is the waterfall's peak.
In the dry season, from around February to May, the water drops a lot. At times it's down to a thin trickle or all but dry, leaving the wide cliff that was once covered in water as bare rock. If your heart is set on seeing a strong flow, coming this time of year may disappoint. We'd suggest checking the local rainfall before you go, or asking a Bueng Kan travel page or the temple Wat Tham Bucha out front before you set off.
Safety in the rainy season
Because this is a forest waterfall fed by a stream up in the hills, in the rainy season you have to watch out for flash floods and water rising fast. If it rains hard up on the hills the water can surge suddenly even when it isn't raining where you are. Swim only in the shallow spots the rangers watch over, stay out of the fast-moving sections, and remember that the rocks get very slippery where there's algae — walk slowly and keep a firm grip.
Entry fee, hours, and facilities
Chet Si Waterfall is inside Phu Wua Wildlife Sanctuary and there's an entry fee of around 60 THB per person. It's open during the day, roughly 08:00–16:00. It's a waterfall you have to walk in to from the parking area — you can't park right at the falls. The entrance out front sits next to Wat Tham Bucha (Wat Phu Wua Chet Si Waterfall), which has a car park, restrooms, and local food stalls where you can grab a bite before or after your swim.
- Parking — there's a lot out front near Wat Tham Bucha. A regular car can make it in under normal conditions, but parts of the road can get muddy in the rain, so drive with care.
- Restrooms — available out front. Bring a change of clothes if you plan to swim.
- Food — there are local food stalls and snacks around the entrance at local prices, but there are no shops at the waterfall itself, so carry drinking water in with you.
- Phone signal isn't reliable everywhere — this is forest, and the signal is weak in spots. Plan for it.
Is the walk in long? How many tiers should you do?
From the car park you walk in along a forest trail, about 800 meters, to reach the first tier — the one most people swim at, because it has a wide rock terrace and shallow spots to soak in. The trail is a natural forest path, shaded but with some ups and downs and tree roots, so comfortable shoes with good grip will keep you safer.
- Tier 1 — about 800 meters from the car park, the main swimming spot, with a wide rock terrace and water spreading across the cliff. Good for soaking and photos.
- Tier 2 — about another 200 meters on from the first, quieter and with fewer people.
- Tier 3 — about another 200 meters past tier 2, more forest walking, good for those who want to go a little deeper in.
- Top tier — the trail gets steeper and more overgrown. Most visitors are happy stopping at tiers 2–3, and there's no need to push all the way up if forest hiking isn't your thing.
You don't have to do every tier
If you're here to swim with family or kids, tier 1 with its wide rock terrace and shallow water is plenty. If you like hiking and want the quiet, carry on up to tiers 2–3 — but don't force yourself all the way to the top.
How to get to Chet Si Waterfall from Bueng Kan town
Chet Si Waterfall is in Seka district, fairly far from Bueng Kan town — about 1.5–2 hours by car. The last stretch is a road into the forest, so watch for the turn into the Phu Wua area and the waterfall signs. The local landmark people use is Ban Don Siat School; from there it's about another 5–6 kilometers to the waterfall. Carry on roughly 3 kilometers past it and you'll reach Tham Phra Waterfall, another falls in the same Phu Wua forest.
- Private car / rental — the easiest option, since there's no public transport that goes right to the waterfall. Rent a car in Bueng Kan town or drive over from Udon Thani, and navigate to Wat Tham Bucha (Wat Phu Wua Chet Si Waterfall).
- Hiring a local driver — if you're not driving yourself, you can hire a car from town or set up a trip that combines Tham Phra Waterfall and other spots around Seka. Agree on the price with the driver in advance.
- Allow extra time — it's a long round trip and the waterfall closes around 16:00, so head out early to give yourself a relaxed swim without rushing back.
Getting ready for Chet Si Waterfall
- Swimwear + a change of clothes — if you plan to swim, since this place is like a water park in the forest. Bring a towel and a waterproof bag for your phone.
- Shoes with good grip — there's both forest trail and slippery algae-covered rock, so closed-heel shoes or water shoes beat flip-flops.
- Drinking water and snacks — there are no shops at the waterfall itself, so bring your own and carry your rubbish back out to dispose of up front.
- Insect repellent — this is real forest with insects and mosquitoes, so you'll be more comfortable putting some on.
- Check the rain and water level — before you go, ask a travel page or locals whether the water is looking good, so you don't make the trip for nothing.
Where to go next from Chet Si Waterfall
Tham Phra Waterfall
Another waterfall in the Phu Wua forest, about 3 kilometers on from Chet Si Waterfall — easy to pair with it on the same trip.
LandmarkPhu Thok
Wat Chetiya Khiri Wihan, with its seven-level wooden walkways winding around the cliff — a Bueng Kan landmark you can combine with a nature trip.
City guideBueng Kan, the full trip
See the things to do, where to eat, where to stay, and travel routes across the whole of Bueng Kan in one place. Plan from the start.
Plan your full Bueng Kan trip — Phu Wua's forest waterfalls, Phu Thok, the Three Whale Rock, riverside eats along the Mekong
See the Bueng Kan guide →