Nepal Has 10,000 Hand-Carved Caves in a Cliff Face — and Nobody Knows Who Built Them

Climb the switchback trail above the village of Chhoser in Nepal's Upper Mustang and a cliff face opens up riddled with square black windows — floor after floor of them, running roughly 50 metres straight up a wall of wind-carved mud rock. There is no staircase on the outside. Whoever carved this reached each floor from within, room by room, using ladders that are still there. Multiply that one cliff by roughly ten thousand across the district, and you have one of the least-understood archaeological landscapes left on earth — inside a trekking region that opened to foreigners only in 1992.

Nobody living in Mustang today claims to know who first dug them, and that isn't for lack of asking. Archaeologists from Nepal's Department of Archaeology and the University of Cologne began the first serious excavation campaigns in the mid-1990s, working with mountaineers because many of the highest caves can only be reached with climbing rope. What they found didn't answer the question so much as complicate it. Radiocarbon dates on wood and bone pulled the earliest burial use back to roughly 1,000 BC — centuries before Buddhism reached this valley — while later chambers were clearly repurposed again and again by people with completely different reasons for climbing up there.

The physical scale is what surprises most first-time visitors. The Jhong Cave complex at Chhoser has roughly forty interconnected rooms across five storeys, cut entirely by hand into compacted mud-sandstone and linked by wooden ladders rather than any single internal staircase. It sits within day-trip range of Lo Manthang, the walled former capital of the Mustang kingdom. Because Upper Mustang remains a restricted area under a special permit system, the caves have stayed comparatively unpicked-over by mass tourism — most of the ten thousand have never been formally excavated at all.

What this means for trekkers

What nobody has recovered yet is a name. No inscription in any excavated cave identifies who ordered the earliest chambers cut, or why a community chose vertical cliff faces over ground-level building in a valley with plenty of flat land. The leading theory ties the shift to periods of conflict and raiding along the old salt-and-wool trade route between Tibet and India, when height itself was a form of defence. It's a rare case where the archaeology keeps generating better questions rather than settling the original one — which is exactly why researchers keep going back. Trekkers on the 12-day Upper Mustang trek or the longer 15-day route walk directly beneath several of these cliffs; our guides can point out which caves are currently excavated and which are simply sealed and waiting.

Source: Wikipedia, 'Mustang Caves', cross-referenced against published excavation records from the University of Cologne Mustang expeditions.

Cover photo: Mohan K. Duwal via Wikimedia Commons (CC BY-SA 4.0).