This is fascinating - go and look at these images, where the artist took photographs of Leningrad during its great seige of WII, and then superimposed parts of them onto modern photographs of the exact same spot in the city, creating seamless images.
Superb work and a wonderful pictorial history lesson. If you do not know about the блокада Ленинграда (the blockade of Leningrad), go and learn. The suffering was immense. It does not justify the barbarism the Russians showed the Germans at the end of the war, but it helps to understand it.
I took the title of this posting from a narration I recall in a film I saw about Leningrad, where the narrator said (in Russian): Leningrad . . . city of heroes, city of bridges . . .