Absolute quiet except for the sound of breathing and footsteps and, in the lower passages, the distant sound of water.

This was the environment the ancient miners entered, thousands of years before electric light or mapped routes or handrails or the infrastructure of modern cave tours.

They entered it with bundles of river cane wrapped together and set alight.

They navigated by the flickering yellow light those torches produced, extending ahead perhaps twenty or thirty feet at most.

Beyond the torch, the cave was perfect black — a darkness so complete that modern visitors who experience it on special tours describe it as disorienting, as physically heavy, as something that presses against the eyes even after they adjust.

The miner who was found in 1935 had gone 2.5 miles into this darkness.