This vibrant and fanciful public housing complex, now an iconic landmark of the work of Austria’s own architectural iconoclast, Friedensreich Hundertwasser, regularly tops lists of visitors’ favourite sights in Vienna. As you can probably tell by the Gaudi-esque shapes and colourful palate, Hundertwasser embraced a playful, environmentally-focused artistic philosophy. He proclaimed that straight lines were “godless and immoral,” that every building should have as many trees as tenants, that rolling, uneven floors were “a divine melody to the feet,” and that access to a window was a basic human right. While entering the building is not permitted (it is a private residence for 52 families and 250 trees and shrubs), the Kunsthaus Wien, located just down Untere Weißgerberstraße, features a small museum and café dedicated to this controversial figure.