Cliff-edge control building to observe channel waters in the area, detect enemy naval targets and provide bearings and co-ordinates for nearby batteries. It dates from WW2 and was intergrated with other fire control positions into the Fortress System of range and position finding. The position is made up of a low profile flat-roofed building of two cells. At the last survey in 1999 it appeared to be structurally complete, minus most of its metal fittings.