It is a spectacular fluvial feature with a geomorphic history extending back 2 million years and encompassing the major environmental changes of the Pleistocene period.

Sun Hole Cave provides a varied fauna radiocarbon-dated to the end of the Late Devensian Cold Stage.

The surface features derived from lead working from pre-Roman times up to the nineteenth century are extremely well preserved.

[3] The Black Rock reserve covers 181 acres (73 ha) of woodland, limestone grassland, conifers and an abandoned quarry.

[5] The 86 acres (35 ha) of Ubley Warren are another site deeply affected by the lead mining in the area which lasted until the 19th century.