Aberhafesp Hall Mound was recorded as a tumulus in the Montgomeryshire Inventory when it was visited by RCAHMW on 14 July 1909. At the time it was described as being 274m (300 yd) south of the parish church, St Gwynog's, and within 182m (200 yd) of the River Severn. It was measured as 5.5m (18ft) in height and 91m (130 yd) circumference.

A subsequent survey of Prehistoric Funerary & Ritual Sites: Upper Severn Valley , Gibson, A M , 1998 and site visits by the Clwyd-Powys Archaeological Trust have concluded that the origin of this very irregular mound is probably glacial.

Claire Parry, RCAHMW, 8 August 2011.

Sources:
Inventory of the Ancient Monuments in Wales and Monmouth I - County of Montgomery , Royal Commission on the Ancient and Historical Monuments of Wales , 1911
Clwyd-Powys Archaeological Trust, Historic Environment Record