I spent almost a year living in a brutalist building in Prague. It was a concrete slab with an huge central courtyard, like a prison yard. You could not access the courtyard, it was dark and dingy. But it was completely full of pigeons. Maybe a thousand pigeons lived there. The inner balcony at the back of the apartment was caked with about 3" of pigeon shit. One day I woke up and found they were power washing the entire inside of the building. This caused the volatilization of several metric tons of pigeon shit into large white clouds over several days.

The building had one other interesting feature, which was an old style sliding-cage elevator, just big enough for two people. The inner gate of the cage was missing, so there was nothing between you and the massive concrete floors sliding past as you crossed each level. From the 5th level down to the 2nd, each white-painted floor featured a giant dark blood stain, in the same general area. This started very wide and got thinner at each floor, so it was obvious someone had lost a leg or an arm, or maybe a head.