Royal Commission aerial reconnaissance on 17th July 2018, during the 2018 drought, discovered partial cropmarks of a probable prehistoric defended enclosure at Parc Wilis, Pen y Mynydd. The enclosure lies just north-west of the farm. Only the curving western side of a circular or oval enclosure can be seen, with a probable gateway terminal on the south side, the whole measuring approx. 75m diameter. Traces of linear cropmarks, which may be related to the enclosure, can also be seen in the field to the north.

T. Driver, RCAHMW, Jan 2019.