A group of three very similar drystone heaps at the corners of each of which are set brick, concrete or stone pillars, the brick capped by concrete. Two examples have pillars set at each of four corners, the middle site has only stone visible. Probably the sites of gun emplacements from WW2, guarding the entrance to Holyhead harbour. Each site about 8m in diameter.

John Latham RCAHMW 8 August 2017

Source: The National Trust Archaeological Survey, Mynachdy, Ynys Mon, 1990 (unpublished).