Middle section.
There are three easily visible carvings here, a large concentric ring motif,
centre shot, a large ?spiral motif, lower right, and a faint double ring
concentric, lower left. We thought that there were the traces of a large ring
touching the spiral carving at one o'clock, and perhaps a smaller one
intersecting this at two o'clock, but this area has so much surface
"noise" that the mind can produce all sorts of
possible circular shapes if you stare at it long enough.