A military training area straddling the A66 in the old county of Westmoreland, Warcop, was first used as a tank firing range in WW2. It now has artillery, tank, mortar and small arms ranges, as well as small FIBUA areas, dry training facilities and the usual lecture rooms in the camp itself.
The artillery impact area isn't very big, and the gun areas are restricted, but it's OK for a day's technical firing. Warcop is also useful as a launch point for adventure training into the Northern Lake District.
This MOD webpage will tell you more.