These photographs by Sergei Mikhailovich Prokudin-Gorskii are incredible. Not least because they were taken between 1909 and 1915, and in colour. But d'you know what I noticed most about them? Everything's so clean. And when there are things that are not clean, it's actual dirt that makes them so. Not pollution, graffiti or litter etc.
Seriously,
wow. I found this from looking at the front page of Wikipedia today.
The article about this photo's subject is here.