Located in Darmstadt, Germany, the Waldspirale apartment-building was designed by Austrian artist, Friedensreich Hundertwasser, and built during the 1990s.

There are other apartment buildings in Darmstadt, but the U-shaped Waldspirale is special. Its diagonal roof is covered with grass, shrubs and trees and the facade follows an irregular grid organization.

Waldspirale has over 1,000 windows, but no two are the same. The handles on the apartment doors and the windows are also unique.

Waldspirale was completed in 2000 and people actually live in it.