This is Stenson Bubble on the Trent and Mersey Canal. When I was a teenager, I used to come here often. It was my playground.
Over the years, some things have changed; but the lock is still the same (more or less). The lock gates have been replaced and the little wooden plank footbridge, which nestled against the stone wall of the narrow roadbridge, is now a metal structure complete with handrail on the open side (probably not a bad idea considering the 20 foot drop into about 2 feet of water).
More boats come through too. As kids, we would hang around for hours, climbing all over the lock gates, waiting for a boat. When one did eventually come, we would be very willing helpers, watching the churning water either filling or emptying the between-gate section, depending on whether the boat was an upper or downer, and then putting our full weight against the gate bar, feet dug in against the ridges along the ground, straining to heave it open to allow passage.
This photo is taken from below the lock. You can just make out the lower gate through the bridge arch.
By the way, having had a canal as a childhood playground, I tend to assume that everyone understands the workings of locks, and was staggered to discover that the children in my first school (for whom 'Canal' meant the somewhat more significant waters of the Manchester Ship canal) had not the first clue about the lock system. If, like them, you are slightly puzzled, but want to know more, click here for a quick and easy animated explanation.
I'm linking this post to Jenny Matlock's Alphabe-Thursday. To see more contributions to this meme, click here.