Update: 9/6/2026

ภาษาไทย

Tham Than Lod Yai

(The Great River-Tunnel Cave)
Chaloem Rattanakosin National Park, Si Sawat District, Kanchanaburi

A Marvel of Nature: The Massive Natural Stone Archway While Tham Than Lod Noi is famous for its dark, water-carved tunnel, Tham Than Lod Yai (The Great River-Tunnel Cave) offers a completely different, awe-inspiring experience. Formed over millennia by the gradual collapse of ancient limestone and the continuous erosion of flowing water, this site has transformed into a colossal, breathtaking natural stone bridge.

The massive rock arch spans an incredible 60 meters wide. The open-air cavern beneath it measures 60 meters long, 40 meters wide, and towering 40 meters high. Through a giant sinkhole on the cave’s ceiling, vibrant beams of sunlight stream straight through to the cavern floor, illuminating the space and allowing large, lush tropical trees to thrive right inside the cave.

Historically, this majestic pass also holds great significance, having served as a strategic military marching route for both invading Burmese armies in the past and Imperial Japanese forces during World War II.

Checking the trail map with park rangers. The hike to Tham Than Lod Yai is a 2.5 km uphill trek (3 hours round-trip); it is highly recommended to start before 01:00 PM.
A site steeped in history: Numerous ancient skeletons were excavated here, proving it was once a prehistoric burial ground. These artifacts are now displayed at the Huai Ong Kot Royal Project Museum in Nong Prue District.
Just 200 meters from the park office, we arrived at the cool, airy Tham Than Lod Noi. Inside, a well-lit 300-meter walkway showcases stunning stalactites and stalagmites.
The exit of Tham Than Lod Noi, where the trail to the great cave begins. ⚠️ Safety Warning: During the rainy season, watch out for falling rocks near the cave mouth; do not linger under the entrance canopy.
The 2.5 km trail markers pointing toward Tham Than Lod Yai.
The trail features some steep uphill climbs—be prepared to take breaks! Proper footwear and plenty of drinking water are essential. (Looking back down the trail).
Crossing the stream via a rustic wooden bridge. Note: During heavy rains, the water can submerge the bridge, requiring a bit of wading.
Arrived! The colossal Tham Than Lod Yai resembles a massive natural bridge, formed by a prehistoric limestone cave collapse.
Giant boulder fields scattered across the cavern floor, remnants of the ancient ceiling collapse.
.
On one of the cavern walls is a historic rock painting of a Naga (mythical serpent). Local Karen communities traditionally believed this sacred cave was once the home of the Naga.
The serene forest stream gently carving its way through the bottom of the great cave.
Looking up at the spectacular giant sinkhole, allowing sunlight to feed the lush trees growing inside the cave.
Another wooden bridge on the far side—let’s keep exploring!
After another 100 meters and one more bridge crossing, you will arrive at the tranquil Tham Than Lod Yai Temple.
Surprised to see cars parked up here? There is actually a 34 km driving route that loops around the mountain from the park office. The road is mostly concrete with some gravel/dirt sections. Sedans can pass, but the final 18 km before the temple is very winding—drive with care! If you are lucky, you might even spot wild foxes roaming this fertile forest.

Travel Tip: If you choose to drive around the mountain directly to the upper cave site near the temple, there is currently no national park entry fee collected here (saving 40 THB for Thais / 200 THB for foreigners).

How to Get There

  • The Jungle Trek: Most adventurers reach this cave by taking the scenic 2.5-kilometer jungle trail starting from Tham Than Lod Noi, passing the beautiful Trai Trueng Waterfall along the way (approx. 3 hours round-trip).
  • By Car: Alternatively, visitors can drive up via a secondary route that leads closer to the site near the Tham Than Lod Yai temple, though a private vehicle or hired local transport is required as there is no public bus service available.

On-Site Facilities & Amenities

Because the park focuses on preserving the pristine nature around the great cave, facilities are split between the two sites:

At Tham Than Lod Yai Area (The Site):

  • Multiple public restrooms are available nearby at the Tham Than Lod Yai temple.
  • Note: No restaurants or campgrounds are available at this upper site.

At Tham Than Lod Noi Area (The Main Park Headquarters):

For full comfort, snacks, and overnight stays, please utilize the main park headquarters down the mountain:

  • Visitor Information Centre & Educational Signboards
  • Park Welfare Shop & Local Restaurants (Open Saturdays, Sundays, and Public Holidays from 09:30 AM – 04:00 PM)
  • Reliable Mobile Phone Signals (AIS & True)
  • Public Restrooms & Showers
  • Accommodations & Camping:
    • National Park Bungalows: Book via +66 34 547 020 / +66 95 619 8981
    • Campsite: 30 THB / person / night (Bring your own tent) or tent rentals available for 300 – 600 THB / night.

Visitor Information

  • Opening Hours: 08:30 AM – 04:30 PM (Open Daily)

  • National Park Admission Fees:

    • Foreigners: Adults 200 THB / Children (Ages 3–14) 100 THB

    • Thai Citizens: Adults 40 THB / Children (Ages 3–14) 200 THB

    • Vehicle Entry Fee: 30 THB per car (Note: If you already paid the entry fee at the main park entrance on the same day, you do not need to pay again).

Contact & Inquiries

Map

Chaloem Rattanakosin National Park, Si Sawat District, Kanchanaburi