The Pentagon is the headquarters of the U.S. Department of Defense and one of the most recognizable government buildings in the country. Public tours are limited and must be booked well in advance, but the building is still a major Arlington landmark.
Most casual visitors pair it with the nearby Pentagon Memorial, which is open outside the secure perimeter and commemorates the people killed here on September 11, 2001. Photography rules are strict around the building, so keep cameras for the memorial area.