This old water tower (designed and built by the engineer Franz Salbach in 1929) is located in Lozenets, Sofia. It is now the home of the +365 art gallery.
The old water tower. (Shot with Pixel 4; Night Sight mode, minor post-processing.)
I visited this place a few days ago, it’s autumn now and the tower looked absolutely magical at dusk… :-)
P.S. (27-Oct-2021) I’ve just remembered that a friend of mine, Nixo, posted a cool (and funny) set of pictures featuring this exact same tower! Take a look! :-)