Pin pillow

I could see that the explanation might need a little more detail. This is the highest rock at the north east corner of my site. The level boards are not oriented to form a square, but the batten running left to right is square with the front two stones with its nearest edge positioned directly above the pin in the corresponding corner stone. I made a little circle of clay on the top of each stone and then tipped some molten lead in to give the little pillow slab with the anchor bolt popping up on the middle like a big drawing pin. The bolt will not act as such, it will just stop the pillar sliding off of its rock and center it on the pillow slab. The lead is molten for only a few moments, but long enough to find its level and solidify into a clean level slab.