The Neue Nationalgalerie is more than just a museum or a building. It is a milestone in the history of architecture, a memorial, an icon. Designed by German architect Ludwig Mies van der Rohe, the building is especially well known for its fifty-by-fifty-meter glass hall. With this singular pavilion structure, Mies van der Rohe set a virtuoso close to his decades-long exploration of "fluid" space. There is hardly another building of his in which the boundary between interior and exterior is as permeable as it is here. In many ways, the Neue Nationalgalerie can be seen as Mies's legacy and the quintessence of his thought. This publication presents the building from today's perspective, but it also features historical photographs taken during the construction period, the building's opening in 1968, and the spectacular exhibitions that took place there in its early years.