Exterior and Concrete Siding Material National Assembly Building (Dhaka, Bangladesh: 1962) 

Originally meant as a Pakistani government building, Kahn's monumental design became the seat of the government of Bangladesh when the country split in two. It's as bold and commanding a symbol of young democracy as the world has ever seen; eight concrete modules envelop a center space cloaked in white marble, while the surrounding artifical lake provides natural cooling and a dramatic backdrop.  Photo 6 of 10 in Design Icon: 9 Buildings by Louis Kahn