This may look like familiar territory for me, another canal lock, but actually this is a couple of hours drive away in the Black Country.
Rushall Canal lies just east of Walsall, and I was there with my father, on the occasion of his 85th birthday, having driven over after lunch from Sutton Coldfield for an afternoon stroll along it. This is Lock 3, which is just north of Five Ways Bridge. You can just see a part of the roof of the bridge at the top of the picture.
Probably better Large.