In the depths of memory

I needed bread tonight so for the first time in ages took the longer walk by the River and Cathedral. The river was low but fast flowing after the storms a couple of days ago. 
I saw this in the little garden area by the River and it stirred a memory that I can't quite grasp. A childhood garden or something....
Busy day at work and trying to catch up on my studying this evening that seems to have drifted.