Taking Valentine Drive and Saracen Close as the North Boundary of the Detention Barracks and its other 3 sides as Bailey Drive, to the north was the Singles Block and Sick Quarters, to the east was the Cookhouse/Dining Hall and possibly some accommodation huts, to the south was accommodation huts and to the west was, I think, admin huts. The entrance was where Centurion Close is. So the dip is where the parade ground was in 1944-1945, perhaps with its east end under the cookhouse, and was definitely flat ground with ‘Soldiers under Sentence’ getting worked almost to death by doubling with backpacks full of bricks. (In fact that did happen to a Rifleman Clayton in the middle of the war, and caused a major uproar regarding conditions in the barracks).
Even going in there as a civilian, it was an unpleasant place to be.