Namtok Tat Hueang (Namtok Thai-Lao)

Namtok Tat Hueang sits on the Nam Hueang river, right where it forms the border between Thailand and Laos, inside Phu Suan Sai National Park in Loei’s Na Haeo district. It’s about 25 km from the Na Haeo district centre and 119 km from Loei town — one of the more remote waterfalls in the province. Entry is free, daily 08:30-16:30.

The falls drop roughly 30 metres over a 40-metre-wide face, making it the largest waterfall inside Phu Suan Sai National Park. The border runs straight through the middle of it, so Thailand and Laos effectively share the same cascade from opposite banks — the kind of detail that gives the “Thai-Lao Waterfall” name in its title more than just marketing flourish.

Flow is strongest during and just after the rainy season, roughly July through December; outside that window the river thins out and the falls lose much of their drama. The approach runs through forest trail inside the national park, with the remote location meaning far fewer visitors than Loei’s more accessible waterfalls — worth factoring into how much time and daylight you budget for the trip out and back.

Watch out: This is a genuinely remote drive on rural roads near the border — start early, fill up on fuel in Na Haeo, and don’t count on phone signal once you’re near the park.

It sits within Phu Suan Sai National Park, which also holds limestone gardens and forest trails worth combining into the same trip, and shares Na Haeo district with Namtok Than Sawan, a second waterfall nearby. Both make sense as a loop out of Loei if you have a full day to spend near the border.