The Hundertwasserhaus in Vienna is pretty much a piece of art. It’s an apartment complex designed with the philosophy that one should live in harmony with nature. This is why you see tons of greenery (trees, shrubs, etc.) growing literally out of the walls of the apartment.
The complex was conceptualized by the Austrian artist Friedensreich Hundertwasser with architect Joseph Krawina. It’s a really interesting place to see as they believed – same as Gaudi – that straight lines are unnatural and if a building was to feel natural, it shouldn’t have straight lines. Very interesting!