While lingering is not recommended for security reasons, you should know it is the largest office building in the world, and covers 4 zip codes. (Army, Navy, Air Force and Department of Defense.Tours are available by online reservation mader 14-90 days in advance. Washington Blvd side, where Flight 77 hit. Photography is allowed at the memorial, but is ”’not permitted”’ anywhere else on the Pentagon groundsA take photos anywhere else on site, and you may face a lengthy interrogation by the Pentagon Police and will probably be asked to delete the images. On a lighter note, the interior courtyard is irreverently referred to by employees as Ground Zero, as it was the target of a number of Soviet missiles during the Cold War. There is no public parking at the Pentagon but it is about a 5-minute walk from the Pentagon City Mall through a tunnel.