1/2 Circle

A stone wall,  3 feet high and  6 feet long, when first viewed from the far side,  turned out to be a curved wall in the shape of the letter J.   A strange way to clear a field!

Was the space in the middle a  deeper at one point?

Evidence of Post Contact Settlement: Update July 19, 2016: Just returned from a trip to the UK: In the highlands of Scotland I spotted  similar structures and learned that they are evidence of habitation of men who raised sheep, and were used to catch one or two particular sheep from a flock.The small flock would be driven along the wall by a Sheep Dog, and held there in a tight little group. The man would be able to grab one at a time, for shearing. So was this construct  a late 8th century when the area was first settled?  Has anyone seen something similar?