Loei Dun

Loei Dun is a wide sandstone rock plain inside Nam Nao National Park, where the Loei stream (Lam Nam Loei) cuts across exposed rock near Ban Huai Kapo in Phetchabun’s Nam Nao district. It isn’t a mountain or a limestone pillar, despite what some older listings claim — it’s closer to a natural stone table you walk out onto, pitted with potholes carved by more than a century of moving water.

The erosion has produced several distinct pothole shapes across the rock surface — round basins, oval hollows, narrow pillar-like cuts, and stretches where the water has undercut the stone into natural bridge shapes. How much of this is visible depends heavily on water level: in the dry season the stream drops and the full pattern of holes is exposed across the rock; during the rains, parts of it stay submerged or running. This is a site that rewards checking conditions before you drive out, not one where every visit looks the same.

Loei Dun only became widely known in the past few years, after a local Nam Nao district official posted photos on social media that went viral in Thai travel press. That’s brought a wave of domestic visitors chasing the same photo, but the site itself remains undeveloped — no boardwalk, no ticket booth of its own, no facilities beyond what the wider national park provides at its checkpoints.

Watch out: because it sits inside Nam Nao National Park’s boundary, a visit isn’t free — budget for the park’s standard entrance fee (200 THB for foreigners, 40 THB for Thai nationals) even though this specific rock formation has no separate gate of its own.

Insider Tip: Go in the dry season, ideally November to February, and arrive early — the lower water level exposes more of the potholes, and the morning light is easier on photos than the flat glare of midday.

It sits within the same stretch of Nam Nao National Park as Tat Yai Waterfall, so it’s worth checking with the park office whether both can be worked into the same visit.