In the least-visited corner of Thailand, pressed up against the Lao border, lies a landscape that stops you cold.
Picture three enormous, elongated rocks rising from the crest of a forested hill, their forms so rounded and so evenly spaced that, seen from above, they look unmistakably like a family of whales surfacing from a sea of green.
The place is called Hin Sam Wan—literally, “Three Whale Rock”—and it went viral only a few years ago after aerial photographs began circulating online. But the rock itself is unimaginably older.
Hin Sam Wan: A Postcard 75 Million Years in the Making
The three stone whales are in fact outcrops of quartz-rich sandstone from the Phu Phan Formation, part of the broader Khorat Group—the sequence of sedimentary rock that underlies much of northeastern Thailand and is famous among paleontologists for its wealth of dinosaur fossils.
That sandstone was originally laid down in ancient riverbeds and floodplains during the Cretaceous period, more than 100 million years ago. Then, roughly 75 million years ago, tectonic uplift pushed those rock layers toward the surface, leaving them exposed to the elements.
After that, wind and rain took over.
Over millions of years, erosion worked unevenly across the stone, exploiting natural fissures to separate and sculpt three massive blocks—the largest roughly 250 feet long—until each took on the long, arching profile of a whale breaking the surface.
The reddish tint coating much of the surface has a similar story: it comes from thin layers of iron oxide left behind by chemical weathering over the same vast stretch of time.
Father, Mother, and a Calf No One Can Reach
The formation takes its name from what you see when you look at all three rocks together—a family of whales swimming in single file: a “father,” a “mother,” and a smaller “calf.”
Curiously, only two of the three—the father and the mother—can be reached on foot. The calf is off-limits because of its position and fragile state, which only adds to the mystery.
Long before aerial photography made Hin Sam Wan famous on social media around 2018, the hilltop was visited almost exclusively by Buddhist monks, who climbed up to meditate amid the wind and silence. Several small wooden huts from those retreats still stand today, scattered among the surrounding rocks.
Getting to Hin Sam Wan
Hin Sam Wan lies within the Phu Singh Forest Park, on a hill in Mueang Bueng Kan district, at the far northeastern edge of Thailand, close to the Mekong River and the Lao border.
Bueng Kan is one of the country’s youngest and least-visited provinces—it was carved out of Nong Khai as recently as 2011—which goes a long way toward explaining why the site still feels like a well-kept secret, far off the usual tourist trail.
Reaching Bueng Kan from Bangkok means either an eight-to-ten-hour bus journey or a flight to Udon Thani followed by roughly three more hours overland.
From the town of Bueng Kan, Hin Sam Wan is about 15 miles to the southeast. The final stretch to the summit is a steep dirt track that most visitors cover in pickup trucks hired at the trailhead for around 500 baht per truck. Each one holds several people, so it makes sense to split the fare with other travelers. Those with their own 4×4 can drive up themselves. Admission to the park is nominal, and from the top, marked trails lead to viewpoints overlooking the rocks.
Best Time to Visit Hin Sam Wan
Unlike many of Thailand’s natural attractions, Hin Sam Wan can be visited year-round, though each season offers a different experience.
Paradoxically, the rainy season, from June through October, is the time Thais most often recommend for photography: the surrounding forest reaches its deepest green, and the contrast with the reddish stone is at its most dramatic. The trade-off is a muddier, less predictable access road.
The cool dry season, from November through February, makes for the most comfortable walking conditions and the clearest skies, which is also why it’s the busiest time of year.
Climbing before dawn to watch the sunrise from the top of the “father whale”—when morning mist still fills parts of the valley below—has become the site’s signature experience.
Other Reasons to Stay Longer
Since few travelers pass through Bueng Kan by chance, visitors to Hin Sam Wan usually make a point of exploring the rest of the province.
The best-known side trip is Wat Phu Tok, a Buddhist temple built into an isolated sandstone mountain and reached by a series of wooden bridges and staircases that wind around the cliff face across seven separate levels—an experience as vertiginous as it is meditative.
The banks of the Mekong are also worth a detour: temples such as Wat Ahong Silawat offer unobstructed views across the river into Laos.
And Phu Singh Forest Park itself holds other rock formations and caves, far less photographed than the three whales but no less strange: one shaped like an elephant’s head, another that calls to mind a miniature version of Egypt’s Great Sphinx.
