The Coed y Caerau Auxiliary Unit comprises a concealed Operational Base at ST37999175, a related Ammunition Store at ST38029178 and a Special Duties Section Station at ST37669147. All three buildings have been well concealed and have concrete floors, brick built end walls and entrance shafts and curved corrugated sheet-steel roofs. Similar bases were built in strategic coastal areas along the length of the British coastline where invasions were expected.
Source: Cadw scheduling description. F.Foster/RCAHMW 22.04.2010