The Tu Lan cave system comprises of more than 20 wet and dry caves, which are thought to be between three and five million years old. Huge caverns, underground rivers and vast dangling stalactites make the caves a big draw for spelunkers (cave enthusiasts) visiting Phong Nha-Ke Bang National Park (although the caves technically lie just outside the park), and the otherworldly landscape even captured the imagination of Hollywood, with Tu Lan featuring as a backdrop in blockbuster Kong: Skull Island (2017).
The existence of Tu Lan was first documented by the British Cave Research Association in 1992, but its existence was known locally for much longer. Additional surveys of the caves took place in 2010, which revealed the true scale of the system. The 2010 caving team included consultants to tour operator Oxalis, who are the leading tour operator licensed to take visitors into the caves.
Touring the caves
The caves can be explored on one-, two-, three- and four-day tours with Oxalis.
All trips begin with a countryside hike, past peanut fields and grazing cattle, to the entrance of the cave system, and include a guided tour through at least two caves and a swim in an underground river. Longer tours take in additional caves (both wet and dry) and include nights in campsites nestled in the surrounding countryside, while the four-day iteration offers the chance to abseil inside the cave.