Pre-war Berlin’s heart beat in teeming Potsdamer Platz, where Europe’s first traffic signal, installed in 1924, regulated the autos and trolleys converging on the center. Overhead, billboards advertising F.W. Murnau’s Der Letzte Mann or Fritz Lang’s Metropolis presided over frenzied masses scurrying from cinema to cafe. But Allied bombing during World War II flattened Berlin’s ceremonial boulevards and commercial monuments, as well as cultural optimism; Checkpoint Charlie replaced four-star hotels in a new concrete desert. Fortunately, the Weimar film machine cranked out reels of footage ensuring the celluloid preservation both the physical aspect and the angst of this modern-age Pompeii: Parts of Joe May’s 1929 film Asphalt (pictured) replicated bustling Berlin street scenes; dystopian set designs from Metropolis captured fears unearthed by machine-age progress. Brown University architectural historian Dietrich Neumann, author of Film Architecture: Set Designs from Metropolis to Blade Runner, tours Berlin’s evolving urban form as represented in pre- and postwar films, arguing that cinema architecture and design helped define and document Berlin’s social and cultural predilections. At 6:30 p.m. Wednesday, April 7, at the National Building Museum, 401 F St. NW. $11. (202) 272-2448. (Jessica Dawson)