Reader Mike H writes:
I was up in Opacum Woods this afternoon. At the top of a hill, there is a stonewall that has a quarter round enclosure with a radiusof about 12 feet. Directly south of this enclosure is a collection of 4 large boulders about 6 feet tall, with a stone wall connecting them to a rock ledge.
The first photo is looking west, there is a spring in the foreground starting underneath the wall, and heading south.The second photo is a view from the other side, looking NE.
The third photo is looking south from about the same spot.
The fourth photo is from the ledge to the south looking east.