🔄 Updated 21 Jun 2026
The first thing to understand before planning a Ubon nature trip is that the season decides what you actually see. Sam Phan Bok looks best when the water is low — late winter into the hot season (roughly December to May) — because the rock potholes are exposed and you can walk among them. Saeng Chan Waterfall is the opposite: you need the rainy season into early winter (October to January) for a proper flow through the rock hole. The sweet spot for catching almost everything is the late-rains/early-winter window, around November to December — the weather is good, the waterfall still has water, and Sam Phan Bok is starting to dry out. The two-colour river (the chalky Mekong meeting the indigo Mun) is sharpest in the dry season, around March to May.
Day 1 — Into Khong Chiam, Pha Taem and the two-colour river
It is about 80 km from Ubon city to Khong Chiam, an hour and a half by car. On the first day we cover the southern side of Pha Taem National Park first — both the rock paintings and the mushroom rocks — then come down to stay near Khong Chiam to catch the two-colour river in the evening.
Day 1
Ubon city → Pha Taem → Sao Chaliang → two-colour river, Khong Chiam
08:00
Leave Ubon city heading toward Khong Chiam district. Stop to fill up the tank and grab enough water for the car.About 80 km, around 1.5 hours · shops are sparse inside the park, so bring water and snacks with you.
10:00
Enter Pha Taem National Park to see the prehistoric rock paintings, roughly 3,000–4,000 years old, on the cliff face above the Mekong. Walk the trail down to the paintings, then loop back up to the viewpoint.Open 05:00–18:00 daily · entry 40 THB for Thai adults, 20 THB for children · the path down is a stone staircase, so trainers are more comfortable · Huai Phai subdistrict, Khong Chiam.
12:00
Stop at Sao Chaliang, the mushroom-shaped rock pillars carved by wind and water over millions of years, just a little before the park headquarters. They photograph well at any time of day.Same park, no extra entry fee · the midday sun is strong, so bring a hat and umbrella.
13:00
Head down for lunch in Khong Chiam town. Pick a riverside place that cooks Mekong river fish — tom yum giant catfish, grilled fish or fish laap.Fresh Mekong river fish is the local highlight; prices go by fish size, so ordering shared dishes works out better value.
15:00
Check in to your stay around Khong Chiam. Somewhere right on the river or near the two-colour river viewpoint is handy. Drop your bags and rest a while to escape the afternoon heat.Riverside places in Khong Chiam range from small resorts to homestays. Book ahead in the cool season because it gets busy.
16:30
Go to the two-colour river viewpoint, where the indigo Mun River meets the chalky, silty Mekong. On a clear day you can see the line between the two distinctly. Sit and enjoy the cool breeze.The two colours are sharpest in the dry season (Mar–May) · in the rainy season both run muddy and the line is faint · you can take a boat out for a closer look at a price agreed with the boat owner.
18:30
Have an easy dinner at a café or riverside spot in Khong Chiam, sipping a drink as the sun sets behind the river.Riverside cafés like Mong Khong Cafe & Camping and Khwam Song Cham have coffee, desserts and simple food. Drinks start around 60 THB.
About where to stay
If you want to fit both Sam Phan Bok and Pha Chana Dai into one trip, we suggest the first night in Khong Chiam, then for the second night either shift over toward Pho Sai or come back to Khong Chiam — your call. Sam Phan Bok is in a different district from Saeng Chan Waterfall, so a little looping saves more time than driving back to the city every day.
🎟️Book the activities in your Ubon Ratchathani trip ahead
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.
🎟️ See all Ubon Ratchathani tours & activities (Klook) Day 2 — Sam Phan Bok, the Grand Canyon of Thailand
Sam Phan Bok is a rocky shoal in the middle of the Mekong where the water has carved out thousands of potholes ("bok" in the local dialect), exposed for walking only when the water is low. It sits in Pho Sai district, about an hour-plus drive north from Khong Chiam along the river. We set out a bit early today, because walking on bare rock in full sun gets brutal if you leave it late.
Day 2
Hat Salueng → boat to Sam Phan Bok → rock formations → back to your stay in the evening
07:30
Leave Khong Chiam and drive along the Mekong toward Pho Sai district. Grab breakfast on the way or pack a box to eat at the beach.The riverside road has lovely views but is narrow in places, so drive carefully · leaving early lets you walk Sam Phan Bok before the sun gets harsh.
09:00
Reach Hat Salueng at Ban Pak Kalang, Song Khon subdistrict — the boat launch for Sam Phan Bok. It is a white sand beach over 800 metres long on the Mekong. Have a wander and some photos before boarding.Hat Salueng is the main boat launch · a chartered boat is priced by agreement with the owner, depending on group size and stops; going as a larger group brings the per-person cost down.
09:30
Take the boat down the Mekong from Hat Salueng to Sam Phan Bok, about 4 km. Along the way you pass rock formations people have given playful names, like the dog's head rock and Pak Bong.In the low-water season (Dec–May) the potholes are clearly exposed and you can walk on the rock ridges · in the rainy season the water floods the bok, so you can cruise by boat but not walk.
10:30
Climb up and explore Sam Phan Bok on foot — the dog's head rock, the angel's vase, and the round water-carved holes that look almost sculpted. You can easily spend an hour walking and shooting photos.Some rock is slippery and gets hot later in the morning, so tread carefully and carry enough water · there is no shade, so wear a hat and sunglasses.
12:30
Head back to shore at Hat Salueng and break for lunch at a beachside place or in Pho Sai town. Isan food and river fish are the mainstays.Places around Hat Salueng open with the tourist season; on a weekday off-season there may be fewer open, so have a backup in town.
14:30
Stop at Hat Chom Dao or a Mekong viewpoint on the way back. Some spots have coloured rock terraces and a lovely view of the river's bend, good for photos in the late afternoon.If you are worn out from Sam Phan Bok, you can skip this and head back to rest — no need to push it.
17:00
Return to your stay in Khong Chiam, shower and rest, then head out for an unhurried riverside dinner.Today involves a lot of walking in strong sun, so leave time to let your body recover before the final day.
Season is the key
Do not expect to walk Sam Phan Bok if you come in the rainy season (Jun–Oct), because the Mekong runs high and floods all the bok. During that time you can cruise by boat to look, but you cannot walk on the rock. If you are set on walking the bok, pick December to May — the closer to the hot season, the lower the water and the more potholes you will see.
Day 3 — Saeng Chan Waterfall and last odds and ends before heading home
The last day is for Saeng Chan Waterfall, also called the "falls through a hole" — water that flows down through a single hole in the rock as one stream, the only one of its kind in Thailand. It is at Ban Thung Na Muang, Na Pho Klang subdistrict, also within Pha Taem National Park. If you are an early riser, you can get up to watch the sunrise at Pha Chana Dai first, since it is the spot where the sun rises before anywhere else in Siam.
Day 3
(optional) Pha Chana Dai → Saeng Chan Waterfall → back to Ubon city
05:00
(For the early-rising crowd) Drive to Pha Chana Dai, the spot where the sun rises before anywhere else in Siam, and catch first light over the Mekong and the Lao bank.It is at the far eastern tip of Pha Taem National Park; the access road is fairly far and rough, so check road conditions with the rangers first · if it is not for you, skip this and sleep in.
08:30
Have breakfast, pack up and check out, then head for Saeng Chan Waterfall at Ban Thung Na Muang.The waterfall is within Pha Taem National Park, so if you bought a park ticket on day one, ask the rangers about reusing it.
10:00
Walk down to Saeng Chan Waterfall to see the stream flowing through the rock hole like a curtain of moonlight. Below the falls there is a spot to shoot upward and catch the water threading through the hole.Best in the rainy season into early winter (Oct–Jan), when there is plenty of water · in the dry season the flow is thin to dry and you may only see the rock hole · the path down is stone and can be slippery.
11:30
If you still have time, stop at the nearby Thung Na Muang Waterfall, or settle into a riverside café for one last coffee before you go.Several riverside cafés have a signature drink named after the two-colour river — worth ordering for a photo before you leave.
13:00
Have a final lunch in Khong Chiam, then drive back to Ubon city. You can pick up souvenirs along the way.You will be back in the city around three or four in the afternoon, so leave enough time to return a rental car or get to Ubon airport.
Getting there and what to prepare
- Your own car is easiest — the sights are spread across Khong Chiam and Pho Sai, and public transport is hard to reach them with. If you fly into Ubon airport and rent a car to drive yourself, you will move around most freely.
- No car? You can charter a tour or local van — there are 2-day, 1-night Sam Phan Bok–Pha Taem tours out of Ubon city that include the boat and a guide, good if you would rather not drive.
- Bring water and snacks — shops are sparse inside the park and out at Sam Phan Bok, and the sun is strong, so always carry enough water.
- Trainers + hat + sunscreen — all three spots involve walking on rock in full sun. Sandals slip easily, especially at the waterfall and Sam Phan Bok.
- Check the season before booking — Sam Phan Bok is walkable when the water is low, Saeng Chan Waterfall is best in the rains. Plan your dates around what you most want to see.
What to eat along the Mekong
The highlight around Khong Chiam and Pho Sai is fresh Mekong river fish — giant catfish, sheatfish and river prawns. Most riverside places cook them as tom yum, grilled fish or laap, eaten with sticky rice and jaew dipping sauce. For the café crowd, there are spots with river views where you can sit, sip coffee and watch the sunset.
Mekong river fishRiverside restaurant, Khong Chiam
A local home-style restaurant on the river, focused on Mekong river fish, small shrimp and river prawns, right by the water — a good fit for lunch on day one.
Riverside caféMong Khong Cafe & Camping
A café right on the Mekong with drinks, desserts, Thai–Isan–Western food and a camping zone. Drinks start around 60 THB, with a panoramic river view.
Coffee with a river viewKhwam Song Cham Cafe
A laid-back riverside café with house-roasted coffee, well-priced cakes and a savoury menu too, where you can sit and watch the river for a good long while — a fine last cup before heading home.
