In 1958, I stayed in the Hotel Deutzer-Hof in Köln. It was a WWII bunker, and it had no windows, only slots through its thick concrete walls. In my room, this "window" looked southwest toward the famous cathedral: this was the view.
Once when I came into the room, I happened to close the door before I turned on the light, and I saw an amazing thing. On the wall opposite the window, I saw this same image, upside-down, with the spires hanging down like stalactites. I was inside a box camera or camera obscura!
I wish I could map the photo. All I know is that it was across the river, northeast of the cathedral.