🔄 Updated 21 Jun 2026
The official name is Khao Ngu Stone Park, in Tambon Ko Phlapphla, Mueang Ratchaburi district. It used to be a limestone quarry, and once the blasting stopped the pits filled with water and turned into a lake, while the straight-cut rock faces were left standing as an odd, striking backdrop. The municipality turned it into a public park with a bridge across the pond, pedal boats, and a concrete stairway up to the caves on the hill. The real draw is getting two kinds of trip in one place — genuine archaeology in the caves, and natural lake scenery down below.
Tham Ruesi — wall-carved Buddha images over a thousand years old
The star of the show is Tham Ruesi. In its main chamber there is a bas-relief Buddha seated in the European fashion with both feet down, around 2.5 metres tall, the right hand in the teaching gesture. Archaeologists place it in the Dvaravati period (roughly the 7th-11th centuries CE), which makes it very old compared with the average temple.
Even more interesting, between the ankles there is a Pallava-script inscription in Sanskrit, which reads as mentioning the name 'Sri Samadhigupta' — thought to be the craftsman or patron who made it. The Fine Arts Department registered it as an ancient monument back in 1935. The Buddha's face has a local cast to it rather than copying Indian art directly, marking it as early Thai craftsmanship interpreting Buddhist art in its own way.
See them all
Besides Tham Ruesi, the hill also has Tham Fa Tho and Tham Chin-Cham, which likewise hold traces of carvings and Buddha images. You can walk between them along the stairway, so if you love old things, leave enough time to cover all three caves.
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Climbing to the caves and the city view
The way up is a concrete stairway the municipality built, steep in places but never for long, and most people reach the cave mouth in just a few minutes. From the top you look out over rice fields and the flat sprawl of Ratchaburi town stretching into the distance, with the green lake below. It's a photo angle plenty of people come specifically to capture.
- Footwear — wear trainers or shoes you can climb steps in comfortably; parts of the cave floor get slippery from the damp.
- Timing — early before 10am, or late afternoon near dusk, when the sun is softer and the photos come out better than at midday.
- Water — carry some up with you, because there are no shops up at the caves.
- Respect — the caves are both an ancient monument and a place of worship; keep the noise down and don't touch the carvings.
Around the lake and things to do in the park
If you'd rather not climb the hill, the area below is easygoing too. A lake walled in by limestone cliffs is a scene you rarely get in town — emerald-green water set against grey rock — and there's a bridge across the pond for strolling and photos.
Pedal boats & feeding the fish
Pedal around the pond, or buy fish food to toss to the schools of fish in the water. Good for bringing kids along.
Bridge across the pond
A photo spot that gets the rock cliffs and the green water in one frame; prettiest in soft light.
Cycling & strolling
The paths through the park are flat, so you can cycle or walk a loop around the lake at your own pace — about 1-2 hours covers it.
Opening hours, entry fee, and getting there
- Opening hours — daily, 08:00-18:00.
- Entry fee — adults 20 THB, children 10 THB (approximate, may change).
- Location — Tambon Ko Phlapphla, Mueang Ratchaburi district, about 8 km from town.
- Getting there — driving yourself is easiest, with parking on site; around 1.5-2 hours from Bangkok.
- Time needed — allow roughly 1-2 hours for the caves and a loop of the lake.
Plan a half-day trip
Tham Khao Ngu is close to town, so you can visit in the morning and follow it with lunch in Ratchaburi's old town or a stop at the market. It works well as the first stop of the day, before the sun gets harsh.
Want to cover all of Ratchaburi's food and sights
See the Ratchaburi travel guide →