Area: 26.3 hectares.
Part of the site is managed as a nature reserve and cave studies centre by the Royal Society for Nature Conservation, the Devon Trust for Nature Conservation, and the William Pengelly Cave Studies Trust. The site area has been increased.
Buckfastleigh Caves are an excellent example of cave formation during the Pleistocene period, and are one of Britain’s outstanding locations for Pleistocene mammals. The cave waters are important for an aquatic crustacean, and the site supports both winter and breeding roosts of a rare bat.
The site is one of three networks of cave passages in separate limestone outcrops around Buckfastleigh. Detailed study has shown that the three networks developed over the same timespan during the late Pleistocene period of Geological history about 150,000 years ago. Furthermore, stages in the development of the caves can be related to the stages in the development of the River Dart. Accumulations of debris washed into the caves during their formation contain important fossil remains which give an indication of the age of the caves. The caves also contain important and spectacular mineral deposits. The wide range of important features found within these caves makes this a most valuable site for the study of late Pleistocene cave formation.
Joint Mitnor Cave has yielded the richest known fossiliferous assemblage of Ipswichian Interglacial age in Britain, and extensive fossiliferous deposits remain in situ. The fauna includes hippopotamus, straight-tusked elephant, wild boar, fallow deer, spotted hyena, lion, and small mammals.
Abundant in the cave waters is the endemic crustacean Niphargellus glenniei, an animal thought to be a pre-glacial relict. The caves also provide an important winter roost site for a large colony of the rare and endangered greater horseshoe bat Rhinolophus ferrumequinum, while the nearby buildings support nursery roosts during the summer months.