Caves have a long eremitic tradition. John the Baptist frequently lived in a cave, and the Celtic saints followed this, probably building on a tradition of caves being used as sanctuaries during times of trouble (for example: the Annals of Ulster, U863, imply caves were used to hide materials from raiders [see also U1063 on the defence of a cave]*). As well as Illtud, Both St Samson (Translation*) and St Kentigern (Translation*) lived in caves.

A non-exclusive list of extant caves associated with Dark Age saints also includes St Baldred's Cave (Info; Info); St Fillian's Cave (Info); St Servanus's Cave (Translation of Life); St Ninian's Cave (Info); and, of course, St Tysilio's red cave (Info)!