The farmstead of Nant-yr-Efail is shown on the 1841 Map of the parish of Bettws yn Rhos as two rectangular buildings perpendicular to one another. A former farm outbuilding recorded in 2020 appears to have been constructed between 1841 and 1880. The structure is constructed from stone rubble bonded by lime mortar.
Reference: Level 1 Historic Building Record, conducted in 2020.
RCAHMW, 2022.