Nant yr Helygen comprises a large deserted dwelling constructed on an earthen platform close to the edge of the Nant Helygen. This was either stone walled or at least partially stone walled, and has associated sith it, a small earth banked enclosure, probably used for small scale cultivation. Also present are five earthen platforms of varying size and form which have been built on the slopes overlooking the stream. The variety of features present may represent several phases of development of this rural domestic settlement.
Source: Cadw scheduling description, March 1999. RCAHMW 18.01.2008