Heavily mined showcave where almost all natural passage has been artificially enlarged making it very difficult to ascertain the actual length or depth of natural passage. The length given is an estimate for the length of naturally joined natural passage. Reaserch continues...
Above text by Tim Gilson.
The original cave system dates from the Jurassic, with later influx of iron-rich minerals coating most of the natural walls, ceiling and floor. This was mined for the ochre and iron ore. The mined length is thought to be about 30 km, dropping to 166 metres below the surface. No complete survey is available, and it is unlikely that any survey could reliably detect which parts are originally natural.
The showcave offers normal tours, as well as caving taster courses. Caving access is available through a leadership system operated by the Royal Forest of Dean Caving Club.