Hundertwasser House

Love it or hate it, this brightly colored, off-center, eco-minded transformation of a drab council block by Austrian hippy artist Friedensreich Hundertwasser in Vienna's Third District is now as much a tourist attraction as the Hofburg or Stephansdom. By declaring war on the straight line and pledging to repay a debt to nature, Hundertwasser covered the facade in a checkerboard of primary colors, added onion domes and ceramic cladding with planted lawns and trees on the rooftops. Inside, the 50 flats were given the disconcerting feature of undulating terracotta floors. Don't miss the nearby Kunsthaus Wien, another Hundertwasser transformation, housing a permanent collection of his art.