Not damn, but dam. I took this snap while visiting the Franconian village of Bamberg, in Germany:
And it reminded me I left the village before exploring what this really was.
The Rhine-Danube canal flows through the city of Bamberg, and the Rhine-Danube canal has plenty of locks. But this is not one of them, and I am not sure why they need to regulate the flow of the river here. It doesn’t look like the water is used for any purposes, such as an historic mill or modern power generation.
It’s on my to-do list to come back one day and figure this out!