Lam Khlong Ngu National Park

Lam Khlong Ngu National Park runs two showcase caves on two separate calendars in 2026. Nang Aen Bird Cave opens for a dated window, 27 February to 26 April, guided-access only; Tham Sao Hin, home to the park’s famous stalactite-stalagmite column, stays closed for the entire season after fast-moving floodwater made the passage dangerous. Neither is a walk-in visit. The 673 sq km of forest around them, in Thong Pha Phum district, Kanchanaburi province along the Tanaosri range near the Myanmar border, stays open regardless of what the caves are doing.

Two caves, two different 2026 windows

Nang Aen Bird Cave is the one that’s actually bookable this year: the park announced a 27 February–26 April 2026 season, with entry through guided groups arranged at the park office rather than a ticket-booth walk-in. Tham Sao Hin, the more famous of the two thanks to its rock column, doesn’t have that option in 2026 at all. High, fast-flowing water inside made the passage unsafe, and the park has kept the closure in place while conditions are reassessed rather than setting a reopening date. The column itself, formed where a stalactite met a rising stalagmite, is cited at around 62.5 metres and locally billed as the tallest such formation in the country; treat the “world’s tallest” version of that claim as the park’s own promotional framing rather than an independently verified record.

What stays open regardless

The hiking trails and two multi-tier limestone waterfalls, Nang Kruan and Kliti, run year-round and need no booking. Trails wind through dense canopy that filters the light into broken patterns, following streams that cut through limestone outcrops, a legitimately quiet alternative to the River Kwai crowds further south in the province. If the caves are closed or out of season when you visit, this is still a full day out on its own.

Watch out: Don’t build a visit around either cave without checking status first. Nang Aen’s window is dated and can close early in bad weather; Tham Sao Hin has no confirmed reopening date.

Insider Tip: Call the park office before setting out specifically for Nang Aen Bird Cave. Guided slots inside the dated window can fill on weekends, and turning up without a booking gets you the trails and waterfalls only.

Planning your visit and getting there

Park entry costs 200 THB for foreign adults (100 THB children) and 40 THB for Thai adults (20 THB children), with the gate open 08:00-16:00 daily. Songthaews from Thong Pha Phum town reach the park entrance; a private vehicle gives more flexibility for the trailheads and waterfalls, which are spread across the park rather than clustered at one gate, and is the easier way in from Kanchanaburi city, a few hours further south. Pack insect repellent, sturdy shoes for muddy trail sections, and drinking water. Facilities inside the park are basic. November to February brings the clearest, coolest hiking conditions; expect swollen streams and slippery trails in the rainy months, which is also when cave access is most likely to be restricted.