Tham Phra Khayang

Tham Phra Khayang is a small limestone cave on the grounds of Wat Suwannaratanaram in Kra Buri district, Ranong, better known locally for ancient rock art than for any grand religious statuary. A roughly 40-metre walkway runs through the main chamber past stalactites and stalagmites, and a set of stairs climbs to a viewpoint over the Kra Buri River and the Myanmar coastline beyond it — at one of the narrowest stretches of the Thai-Myanmar border. Entry is free, open daily 08:30-16:30.

What makes the cave notable isn’t ornate carving but age: faded rock paintings and pottery fragments found inside are believed to date to prehistoric use of the site, and researchers have suggested the cave sheltered early inhabitants of the Kra Isthmus long before it became a place of Buddhist merit-making. The name itself comes from a local legend about a “kha yang” — a set of three lashed wooden poles once used as a restraint — tied to a folk story about a father and son from the area. It’s passed down as oral history rather than documented fact, and worth hearing from a local guide rather than repeating as settled history.

A colony of bats roosts in the cave’s darker sections, and the walkway can be slippery where water seeps through the limestone — bring a torch or phone light, since the artificial lighting inside is minimal, and wear shoes with grip. Outside the cave mouth, a short nature trail winds through mangrove and coastal forest where kingfishers and the occasional rail babbler turn up for anyone patient enough to look.

Insider Tip: The cave itself takes only 20-30 minutes to walk, but the staircase to the river viewpoint is the part worth the trip — go in the late afternoon when the light over the Kra Buri River is best.

Watch out: The cave floor is often damp and uneven in low light — take it slow on the walkway, especially with children, and skip it if you’re prone to claustrophobia in tight, unlit passages.

The turnoff is on Phet Kasem Road between Ranong and Chumphon, with parking near the wat. It pairs naturally with Lam Nam Kra Buri National Park, which follows the same river, and with the Kra Isthmus viewpoint marking the narrowest point of the Thai peninsula, both in the same district.