Actually, a bit more than that, on the left is the end of an old mill tailrace. And quite the mill it was, with a proper penstock and wheelpit and everything. Not much left now. But, having given water a channel, it tends to keep using it even after a century or so. I just liked the geometry of everything, so I snapped a snapshot as I took my work photos.
In other news, do you know how tedious it is to unravel umpteen hydrangea buds to squish the little worm in residence in each one? Oy.
You are amazing and a gem!