This is a solargraph. A photo with an exposure time of half a year. The white streaks are the sun in the sky. The outer left streak is summer solstice (June 21), the outer right streak (appearing dark blue) is winter solstice (December 22).

No colors have been added, but the contrast has been highly enhanced. Remarkable is the white edge over the roofs, which is really on the photo.

To get a better idea of what you see, here is a clue. The photo is made with a pinhole camera made by Tarja Trygg of solargraphy.com. Visit this site to see more solargraphs and find out how to make one yourself...