Tham Khao Wong Forest Park (Phu Wai Cave)

Tham Khao Wong Forest Park protects a limestone cave system in Ban Rai district, Uthai Thani, on the western forest boundary that meets Phu Toei National Park in neighbouring Suphan Buri. Entry is free, the park opens daily 08:30-16:30, and the main draw is Phu Huai Cave — a chamber large enough to explore for about an hour with a guide.

Inside Phu Huai Cave

The limestone cliffs at the entrance rise steeply before opening into a tall, well-ventilated chamber lined with stalactites and stalagmites. Local guides point out a few named formations along the route: the Million-Year Pillar, a crowned rock, and a rock face said to resemble Guan Yin. Passages continue through to the far side of the mountain, and the cave shelters nine recorded bat species alongside crickets and cave spiders — expect some noise and movement overhead as you pass through the darker sections. Guides are arranged at the cave entrance rather than booked ahead; there’s no fixed fee structure for this, so bring small cash. A second, smaller cave — Pha Mali Cave, also known as Naga Cave — sits just behind Phu Huai Cave. It’s a shorter, deeper cavern with its own stalactite formations and far fewer visitors reach it.

Above ground: Phu Huai Peak

For those with more time, Phu Huai Peak rises to about 700 metres above sea level behind the caves, cloaked in dry deciduous dipterocarp forest. The trail up isn’t a manicured tourist path — it’s a genuine forest walk, and the payoff is a wide view over the Ban Rai valley rather than a built viewpoint deck.

Atmosphere and timing

This is a working provincial forest park, not a polished attraction — expect a handful of other visitors at most, mostly Thai day-trippers passing through Uthai Thani rather than international tour groups. The dry season (roughly November to April) makes for a firmer, less slippery trail both in the cave and on the peak trek; during the rains the limestone floor gets genuinely wet underfoot.

Insider Tip: Ask for the guide as soon as you arrive rather than looking around the entrance first — on quiet days there may only be one or two guides on site, and they can be walking another group.

Watch out: Low passages inside Phu Huai Cave force you to duck in places, and the bat colony means the air can carry a strong, musty smell near the roosts — not ideal if you’re sensitive to that.

Tham Khao Wong Forest Park sits at Ban Rai, Uthai Thani (map), inside the same Uthai Thani cave country as Tham Kao Kong Chai and the Giant Tree at Ban Rai — worth combining into one day if you’re driving the district’s back roads. Call 0 5651 4651 for current guide availability.