The War Office requisitioned the area in 1938 from the Cawdor Estate, and many ruins of the former settlements that belonged to the 53 farming communities, which had to be relocated, can still be seen. The land was returned to farming after the Second World War, but in 1951 the Korean War saw its reactivation for range use, which has remained in being ever since. Nevertheless, farming has also continued alongside the range’s primary use, with flocks of sheep and, in the winter, cattle as well.
Castlemartin is the largest single part of ATE P, covering about 5,900 acres (2,390 hectares) of freehold land on the Pembrokeshire Coast National Park. The range is open to all regular and territorial Army, Cadet forces, other services and some overseas forces. But in particular Castlemartin is the only UK Army range normally available for armoured units for direct-fire live gunnery exercises and associated manoeuvres, with both on-land impact areas and a large offshore safety area. The facility is therefore mainly used for so-called ‘mounted’ and ‘dismounted’ (i.e. in-vehicle and on foot) field firing up to company level; but when such exercises are not under way it is also used for dismounted ‘dry’ training (i.e. without live firing) across most of the area. It is also used by civilian organisations and research establishments.
During non-firing periods the public have access to a section of the Pembrokeshire Coast Path – from Trevallen, via Stack Rocks, to the lower Warren Road.