The Barcelona Pavilion (it's really small, with such big ideas)

All planes and overlapping spatial volumes, it remains the hardest building in Barcelona to draw. Originally built as the German Pavilion for the 1929 World’s Fair, the pavilion was the last of Mies van der Rohe's works before he emigrated to the United States. It is considered a key work of both his and the “International Style” movement for its spatial fluidity. The simple, horizontal structure contains his trademarks: precision, fluidity of space, and abundance of “pure” materials. The present structure (1985) is a faithful reconstructed copy of the original.