Circular

If you scroll down you'll find this, along with other photos that make you wonder why the fools messed with the original stones that seemed to be interesting enough:

http://www.vcoiad.net/kol/Atlanta/index.html

It's captioned: I like the fact that the circular stone wall is only six inches high, tops, and there's still a designed entranceway. Maybe they planned to make the wall much taller but got bored. No good lazy Atlanta Indians. Or maybe this is Calvin's effort "The Triumph Of Perseverence."