Rumbling Hole

Rumbling Hole is a cave on Leck Fell, in Lancashire, England. Its entrance is a 50-metre (160 ft) deep fenced shaft, and it rapidly descends a series of pitches to a low aqueous passage that has been connected to Lost Johns' Cave. It is part of the Three Counties System, an 87-kilometre (54 mi) cave system that spans the borders of Cumbria, Lancashire, and North Yorkshire.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).