A password will be e-mailed to you.

Tham Khoun Xe is a remote river cave in Laos and one of the largest in the world, with some passages reaching 120 m tall and 200 m wide. Even some of the stalagmites are 20 m high. It is also little explored by foreigners, as after the first explorations in 1905 it was closed to outsiders for 90 years and only reluctantly re-opened in 2005.

RELATED: This filmmaker travelled 80,000 kilometres to produce this stunning drone videoTham Khoun Xe cave river

The Xe Bang Fai River, which runs through the cave, originates on the border of Laos and Vietnam. On its route to join the mighty Mekong the river passes for 7 km under the Nakhai Plateau, creating this subterranean channel.Tham Khoun Xe cave river

Beijing-based photographer Ryan Deboodt was recently lucky enough to spend two days exploring and filming the cave, beyond the areas usually open to visitors. Along with his standard arsenal of camera equipment, Deboodt also brought a drone, which allowed him to capture staggering views of the interior.

RELATED: Discover tours of LaosTham Khoun Xe cave river

The cave has been known to the local people for centuries, who have fished in the river and scaled the mighty entrance walls to harvest birds’ nests for soup. Legend has it that the cave is inhabited by protective spirits, who will save those who fall from the sheer cliffs while climbing and they will also handily fix musical instruments if you leave them overnight.

via Ryan Deboodt / Instagram

Adventurers wanted

Live & travel off the beaten path with our email newsletter. Weekly travel tips, cool things to see, and more. No spam, ever.