Royal Commission aerial photography on 24th July 2008 recorded earthworks of a possible outer annex to Moel Hiraddug hillfort (NPRN 95092) on an elongated promontory above Foel Fferm. The earthwork enclosures the rim of the promontory, extending approx. 91m north-south. It is not shown on the main published plan in the excavation report.

T. Driver, RCAHMW, 29th September 2008.