A curious chronology - ceremony on a modern causeways built over older stone walls

The second (possible) mound made of soil was at 'A' (see previous post). From 'A' I went up to 'B' where you touch the edge of a site (at 'E') which I knew about and was saving for last. Meanwhile I wanted to get down into that ditched swamp to have a look around. Around 'C' I was enjoying the openings through the old stone walls, and did see a couple piles near one such opening.

 

What was most interesting, though, was the topography of the ditched swamp. Here, some machine had dug 5-8 foot deep trenches through the wetland, throwing the removed dirt and soil up in a bank running alongside each ditch. It must have been a substantial effort but, since it remains a rock swamp, why drain it? Could it affect a water level somewhere else? I don't know.
So here we are looking at a causeway built across the area, rising above the lower ditch (on the left) and slightly above the original ground level - as visible in a bit of older stone wall.

Note that in the foreground on top of the causeway is a ceremonial structure.

It is a 'U', usually taken to be kind of prayer seat. But the causeway came after the stone wall and the 'U' must have come after the causeway. So it is a distinctly modern structure.

View in the other direction (you can just see another pile):

closeup:

So, here is a little ceremonial site built after a machine trenched the whole area. Not sure why it was trenched, not sure who would come later and build these two structures. Up at 'E' the integration of wall with pile indicates an earlier stage of ceremony. I'll just show one picture:

You can check out 'E' yourself or read my previous, somewhat fanciful, account: http://rockpiles.blogspot.com/2011/03/monsters-gods-or-rocks-of-power-site-at.html