Spotted at the Churnet Valley Railway, this steel water tower.I'm pretty sure it's not an original railway structure, but then the railway hasn't built it from scratch either. My guess it the tank was bought in and mounted on new steel legs.
A useful industrial structure, the modelling challenge would be the raised stars on the panels. Ideally, make one and cast the rest in resin. At least the "livery" is simple enough - grey with a touch of brown and green weathering powders.