The Hamburger Bahnhof - Museum für Gegenwart (literally, "Museum of the Present") is the most important contemporary art museum in Berlin. Inaugurated in 1996, the museum is housed in the only ancient railway station still existing (Berlin-Hamburg station, one of the oldest in Germany), which has been converted into a museum space. The museum's exhibition space encompasses over 13,000 square meters. The collection housed inside the museum includes the collection of Erich Marx, the true heart of Hamburger Bahnhof, with works by artists such as Anselm Kiefer, Joseph Beuys, Andy Warhol and Roy Lichtenstein, as well as many other contemporary artists. Among the best known pieces, the installations by Joseph Beuys and works such as Warhol's “Mao”. In addition to paintings, the museum's collection also houses films, drawings, videos and multimedia installations. The collection also includes numerous works donated by the Neue Nationalgalerie and since 2004 it has also hosted the important Flick collection. The museum also organizes important temporary exhibitions.