Hat Chom Dao or Kaeng Chom Dao

Hat Chom Dao is a stretch of granite riverbed on the Mekong at Na Tan, in Ubon Ratchathani province, that only exists as a beach for part of the year. When the river drops during the dry season, roughly November to April, the water retreats to reveal a wide band of sand and wind-and-water-carved rock — locals call the sand section Hat Chom Dao (“Star-Viewing Beach”) and the rock section Kaeng Chom Dao (“Star-Viewing Rapids”), and most people use the two names interchangeably for the same site.

At its driest, the exposed area stretches close to 2 km wide, threaded with more than a dozen small “emerald” pools gouged into the granite by centuries of erosion, along with named formations and nearby caves such as Tham Ta-uan and Tham Ta-ma. Walking between the pools means crossing wet, uneven rock, so grip matters more than speed here. Families picnic on the flatter slabs while the shallower pools warm up enough for wading; the main river channel runs close by and shouldn’t be treated the same way as the still pools.

Watch out: This site is entirely seasonal. Outside the dry season the Mekong reclaims the whole area, so a visit timed for the wrong month means driving out to nothing but open river. November and December, when the water is at its lowest, give the clearest views of the rock formations and pools; by the wet season (roughly May-October) none of it is visible.

Insider Tip: Early morning is genuinely worth it here — the granite holds the night’s cool through sunrise, and the low-angle light makes the pools and rock textures far more photogenic than the flat glare of midday.

Getting here means a drive out to Na Tan district on the province’s eastern edge along the Mekong — there’s no direct public bus, so a car, hired driver, or local tour from Ubon Ratchathani city is the practical option. Combine it with Kaeng Sam Phan Bok or Ban Song Khon Sam Phan Bok further south along the same river stretch to make a fuller day of Ubon’s Mekong rock formations.