Hole #11, I think, hit bedrock. Rocks in the bottom to hold the roofing paper & cardboard in place. Trying out the PVC anchor.

With everything pre-wet, poured the concrete and inserted the anchor. I would have dug this hole further north, but the footing of the tent was in the way.

So the anchor is attached outside of the post, the idea being to line up post #11 with #12 & #13, so that the joist can run in a straight line.

Rocks for hole #12 also.

This won't need an anchor since #11 & #13 have them.

This shows how it lined up with #12. #13 is at the right end of the joist (not in this image).