The Hundertwasser House is an apartment building in Vienna designed by Friedensreich Hundertwasser who was considered an architectural rebel. His vision was of "free architecture for all," meaning without standards, specifications or straight lines — kind of like Dr. Seuss!
Park Güell is a public park in Barcelona, Spain with gardens and some of the most interesting architecture in the world, including the fantastically shaped roofs. Built by famous Spanish architect Antoni Gaudí, known for his flamboyant style.
La Pedrera ("stone quarry") is the more popular name for Casa Milà, designed by architect Antoni Gaudí, who created a roof with sentinels to stand guard, and took six years to build (1906-1912). In 1984, it was declared a World Heritage building by UNESCO. You can even take a tour of this spectacular building!