🔄 Updated 21 Jun 2026
Tham Khao Luang sits on Khao Luang hill in Thong Chai subdistrict, Mueang district, about 5 km west of Phetchaburi town and Khao Wang (Phra Nakhon Khiri). The hill is very low — the highest point is only around 92 metres — so there's no serious climbing. But inside is a limestone cave with several connected chambers, stalactites and stalagmites, Buddha images lining the walls, and the highlight everyone comes for: the beam of light dropping through the cave roof.
Why come to Tham Khao Luang
This cave doesn't stand out for its size — it stands out for the light. There's an opening in the cave roof that lets sunlight drop down in a straight shaft, and when it hits the Buddha images and the dust in the air, it looks like someone set up studio lighting, even though it's pure natural light. Most people come to photograph exactly this moment, and that's why a small cave like this is far more famous than its size suggests.
The other thing that gives the place weight is its history. Tham Khao Luang was a cave King Rama IV was fond of and visited often back when he was based in Phetchaburi. Later, King Rama V had dozens more Buddha images added inside. Walking through, you're moving through a place where important figures of the past actually stood.
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The light beam — when to go to catch it
This is the crux, because the beam isn't there all day — it depends on the angle of the sun. The time the light drops through the opening most clearly and beautifully is roughly 9:30–11:00 am. Later than that the sun gets too directly overhead and the shaft shortens. And on a cloudy, overcast day, the beam fades out or disappears entirely.
Want the good light shot? Do this
Go on a clear, sunny day and enter the cave around 9:30–10:30 am for the strongest beam · The seasons with frequent clear skies run from the cool season into early hot season (Nov–Mar) · Avoid rainy or overcast days — no sun means no beam.
What's inside the cave
The cave is divided into several connected chambers and you can walk a loop around them. There are a few spots where people stop to take photos and pay their respects.
- The light-beam chamber — the hall with the opening in the roof, where the shaft drops onto a Buddha image in the middle of the room. This is the main photo spot.
- Rows of Buddha images — dozens of Buddha images, both those made in the Rama IV era and those Rama V had added later, including a reclining Buddha.
- The large central Buddha — the big Buddha image inside the cave where people come to pray and make wishes.
- Stalactites and stalagmites — the walls and ceiling are full of limestone formations in different shapes, the natural backdrop of the cave.
There's some lighting inside to help, but many corners are still dim. It's better to wear shoes you can trust on damp ground, because parts of the cave floor get slippery from the moisture.
Getting there — how you go up to the cave
If you drive yourself, you can park at the temple lot at the bottom (around Wat Bun Thawi). From there small songthaews take you up to the foot of the cave stairs for about 15 THB per person. It's a short distance — only five or six hundred metres, under five minutes — so you can also walk it, though it's a fairly steep climb.
- From Phetchaburi town — about a 10–15 min drive, well signposted; turn off into the lane toward Khao Luang.
- From Bangkok — take Phetkasem Road (Highway 4) toward Phetchaburi, around 2 hours, then turn off following the Khao Luang signs.
- No car — take a minivan or coach to Phetchaburi, then a motorbike taxi or local songthaew in town out to the foot of the hill.
Watch out for monkeys
The way up to the cave has a lot of monkeys, like many of the hills in Phetchaburi, and the ones here are so used to people that they'll grab things. Watch your plastic bags, water bottles, sunglasses, hats, and phone. Don't walk around showing off food, and don't tease the monkeys. If you're carrying a bag, zip it shut tight.
Simple monkey defence
Keep food zipped away in your bag · Don't walk around holding a plastic bag — the monkeys read it as food · Hold your phone firmly when shooting photos, and don't hold it out near a monkey.
Opening hours and cave etiquette
- Opening hours — Mon–Fri roughly 9:00 am–4:00 pm · Sat–Sun roughly 8:00 am–5:00 pm (go mid-morning to catch the light beam).
- Entry fee — generally no admission charge, as it's a cave on temple grounds, but there's a donation box to help maintain it. The songthaew up the hill costs about 15 THB/person.
- Dress — it's a sacred site, so dress modestly; avoid spaghetti-strap tops or very short shorts.
- Etiquette — take off your shoes at the marked points, keep your voice down, and don't climb on or touch the Buddha images.
What to pair it with nearby
The nice thing about Tham Khao Luang is that it's close to several of Phetchaburi's best spots, so it's easy to build a half-day trip around it.
Khao Wang (Phra Nakhon Khiri)
A hilltop palace from the Rama IV era, only about 5 km from Tham Khao Luang. Take the funicular or walk up for views over Phetchaburi town.
Phetchaburi old town
A district of old temples, craftsmen, and cafés along the Phetchaburi River — good for a stroll and a snack after the cave.
Phetchaburi sweets
Mo kaeng custard, thong yip and thong yot, and palm-sugar cake are sold all over town — easy gifts to take home.
Half-day trip: Tham Khao Luang + Khao Wang
Catch the cave light first, then on to Khao Wang
Want to do Phetchaburi properly — caves, palace, sea, and the food
See the Phetchaburi travel guide →