Sam Phan Bok

Sam Phan Bok

Entrancing Mekong scenery

More on Khong Chiam

They call it the “Grand Canyon of Siam” and some have even compared it to the surface of the moon: a continuous current of rock notched with 3,000 holes, known in the Lao/Isaan language as Sam Phan Bok. Though difficult to reach in a distant corner of Ubon Ratchathani province, the other-worldly landscape and Mekong River scenery make it worth the effort.

Travelfish says:

The 3,000 impressions (certainly it’s an exact count!) look like they were carved out of the rock by a giant ice-cream scooper—a landscape that would make a fine filming location for a sci-fi flick set on the surface of another planet. Sam Phan Bok (it rhymes with “on Ron’s joke”) doesn’t look anything like the real Grand Canyon, but it certainly is one of a kind.

Hole #1,937. : David Luekens.
Hole #1,937. Photo: David Luekens

Much of the rock submerges during the rainy season in an ancient process that helps to polish and sculpt the cavities. Turning into miniature mirror-like ponds of rainwater in May and June, some of the holes are shaped like hearts or Mickey Mouse’s head. When dry, locals lay down mats to enjoy a meal in some of the larger and comfier depressions. Dry season also sees the Mekong narrow to a mere 56 metres across, supposedly its narrowest point south of China.

Legend has it that a greedy king once left a dog here to die after it loyally guarded a treasure discovered in one of the holes. Sure enough, one of the larger rock formations looks convincingly like the head of a dog, some sort of retriever, gazing at the river. Another formation has a protrusion resembling a flower vase; give it a good rub and winning lottery numbers might come dancing into your mind, or so they say.

Perhaps Medusa was out for a cruise that day? : David Luekens.
Perhaps Medusa was out for a cruise that day? Photo: David Luekens

The rocks stretch between the river and a grassy embankment for some 10 kilometres; you could easily lose an entire day wandering the smooth slopes and drifts. At one point the rock gives way to a steep incline of powdery beige sand with tall grasses that suddenly reminded us of an ocean-side dune in North Carolina. In other places, the rocks shift from shades of grey to fiery orange and jet black.

From the comfort of a wooden longtail boat you can see the almost 90-degree rock walls that explain why they call Sam Phan Bok a canyon. The rocks tower far overhead when the water is low, but after a solid few months of rain they appear as nothing but another natural surface slapped by the Mekong’s bubbling brown water.

Hand-painted numbers tell you how high the water is. : David Luekens.
Hand-painted numbers tell you how high the water is. Photo: David Luekens

Long before it became a tourist attraction, Sam Phan Bok was known to be a particularly good place to fish due to the shifting currents and underwater holes that leave fish at the river’s mercy. You can still see plenty of locals seated along volcanic rocks on both the Lao and Thai sides, repeatedly dipping their broad bamboo nets into the river.

Sam Phan Bok is best visited around sunrise or sunset, when the air is cool and reflections of the sun shimmer amid the thousands of holes. During our late June visit, a rainshower rushed in from the west and unleashed a five-minute dowpour before carrying on into Laos. In its wake, a double rainbow materialised in the south as the sun emerged from dark clouds to dip into the river.

Sure beats a fishing pole. : David Luekens.
Sure beats a fishing pole. Photo: David Luekens

Depending on a given traveller’s style and budget, there are a few ways to approach Sam Phan Bok. The cheapest is to simply walk down to the rocks on your own and aimlessly wander around. Another option is to pay 50 baht per person for a songthaew to drive you down towards the boats, which cost 500 baht for a 30-minute trip or 1,000 baht for a full hour. The songthaew driver (or his young son or daughter) may also serve as a guide for no extra charge, though tips are appreciated. They speak little or no English, but at least they can lead you directly to some of the more interesting rock formations.

At time of writing there is no entry fee to visit Sam Phan Bok, though we won’t be surprised if the Thai government declares it a national park at some point. A couple of small restaurants are located near the entrance, and a few resorts are found along the access road.

Get out and on the water. : David Luekens.
Get out and on the water. Photo: David Luekens

Sam Phan Bok is a great way to cap off a day that could also include Pha Taem National Park and its cliffs and waterfalls, which are all located off Highway 2112 on the way north to Sam Phan Bok from Khong Chiam. The scenic ride takes you past forest and rice paddy on a sparsely trafficked two-lane highway.

Transport information

Sam Phan Bok is located near the town of Song Khon, a 75 km drive north of Khong Chiam along Highway 2112. Ubon Ratchathani is 115 km to the southwest along highways 2050 and 2337, and Mukdahan is 130 km to the north along highways 2034 and 2242. The turnoff is sign-posted in English. You'll need your own wheels to get here; consider hiring a car or motorbike—with or without driver—in any of the three destinations mentioned above. December to June is the best time to visit.

Contact details for Sam Phan Bok

Address: Near the town of Song Khon, 75 km north of Khong Chiam
Coordinates (for GPS): 105º23'41.9" E, 15º47'43.96" N
See position in Apple or Google Maps: Apple Maps | Google Maps
Admission: Free

Reviewed by

David Luekens first came to Thailand in 2005 when Thai friends from his former home of Burlington, Vermont led him on a life-changing trip. Based in Thailand since 2011, he spends much of his time eating in Bangkok street markets and island hopping the Andaman Sea.

Tours in Thailand


These tours are provided by Travelfish partner GetYourGuide.


Our top 4 other sights and activities in and around Khong Chiam

Pha Taem National Park
Pha Taem National Park

The vantage point for Thailand's earliest sunrise

Wat Tham Kuha Sawan
Wat Tham Kuha Sawan

The crown of Khong Chiam

Sirindhorn Reservoir
Sirindhorn Reservoir

Beaches and dancing shrimp

Kaeng Tana National Park
Kaeng Tana National Park

Isaan’s longest suspension bridge