Dinmoor quarry is one of the Penmon quarries, with Penmon Park (NPRN 415188) and Flagstaff (NPRN 40625) that have been worked since the sixteenth century. The quarry opened on the site of the barracks for Telford's workmen and it was worked intermittently during the twentieth century. The quarry provided stone for the construction of the Seaforth Container Terminal from 1968.

On early editions of the Ordnance Survey series (Anglesey XV.2 1) dated 1889 and 1900, small-scale disused quarry features are shown. The third edition (Anglesey XV.2) from 1919 onwards shows major quarrying works. The complex is currently disused and it has been photographed by the RCAHMW during aerial reconnaissance.

Source: David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology

RCAHMW, 1 November 2011.