"Terrorist Headquarters, Beirut" is actually El Miradero, the unusually styled mansion built by Leslie Brand that now serves as the Brand Library and Art Center in Brand Park.
Before this sighting, my favorite instance of Glendale on film would be from Double Indemnity, which prominently features the Glendale train station as the departure point for a murderous plot. Are there any other movies that feature Glendale prominently?
