This string is level, showing the large "foundation gap" we have to deal with for our run. I actually bought a dog pen for a run, but we need to put the foundation underneath. We have pavers (foreground, 6x9 inch, about 2 inches deep), and a few cinderblocks). We could build a wood frame, and fill in with hardware cloth, and somehow pin the frame to the ground. Kind of at a loss, so suggestion welcome!