Tower near Top

One of those rare moments when we saw nobody on the wall! Oh, well it wasn't all that rare. Once we made it about 3/4 of the way up the steady hordes of tourists waned to a mere trickle and eventually we had most of the top stretch of the Wall totally to ourselves. It was really cool! This is one of the structures atop one of the towers on the wall. I have no clue what it was used for. Just interesting to look at.