A leap in the dark. Someone I know went on a work-sponsored 'team-building' outward bound course for a weekend in the Lakes that involved sleeping out overnight at the Hardknott fort. I love your black and white picture, but it doesn't quite capture the fact that, in places, the remaining wall is about 2 feet high on one side but, because the land slopes away, about 5 or 6 feet the other side. In the middle of the night, when the chill night air took its toll on his bladder, my friend hopped over the wall to answer nature's call and went a bit further than he bargained for...

I guess that's the fall of the Roman empire. :-)