The "V" of land between Townsend Rd and Garrison Rd, in northern Shirley

I have written about this place before. Visited it again from above and then again from below. From above, in the northern part of the lower left blue outline, I was walking along on what seemed an old road. A low stone wall on the downhill side then, on the uphill side, a bank and a higher stone wall. But it was more a highway than a road - maybe thirty feet wide. 

I came to a place where there it looked like there were rock piles inside the road.

What do you make of this (same from above):

and this:

So I don't think it was a road I was walking along. More a broad terrace.