A cache placed near some World War 2 ruins on Dartmoor.
I believe the larger building was a shelter for recruits to practice stripping and re-assembling their gun and learning how to shoot. The smaller building next to the cache was the latrine block - the galvanised urinal can clearly be seen.
The water for these buildings was stored at the nearby water tank (See my other cache) - which in turn was pumped up from a pump house just above the bridge over the River Ashburn.