Fodor's Expert Review Pentagon

The headquarters of the United States Department of Defense is the largest low-rise office building in the world. Approximately 26,000 military and civilian workers arrive daily. Astonishingly, the mammoth structure, completed in 1943, took less than two years to construct. Following the September 11, 2001, crash of hijacked American Airlines Flight 77 into the west side of the building, the damaged area was removed in just over a month and repaired in a year. In this same area is the America's Heroes Memorial and Chapel, which pays tribute to the civilians and military members killed in the attack. South of the building is the 2-acre outdoor Pentagon Memorial, with its 184 benches commemorating the lives lost on 9/11. Tours of the Pentagon are free and last about 60 minutes, including a presentation and approximately 1½ miles of walking.