The Pentagon replaced 17 office buildings in downtown DC when it opened in 1943. It has five sides, five floors above ground (plus two basement levels), and five ring corridors per floor. Although there are over 17 miles of hallways, it takes no more than 7 minutes to walk between any two points. The Pentagon houses the headquarters for the Army, Navy, Air Force and Marine Corps. Over 23,000 people work in the Pentagon on a daily basis.
If you know someone who works at the Pentagon, he or she can escort a small group. For most people, that is not an option. Groups up to 90 people can set up a tour through their state representative's office in Congress or the Senate (links below). Tours can be requested between 15 and 90 days in advance, and are conducted 5 days a week. Foreign nationals and non US citizens must contact their embassy in Washington DC to arrange a Pentagon tour. Further information including Frequently Asked Questions is at the Pentagon Tours website (link below).
The Pentagon is actually a small city. It has restaurants, cleaners, banks, dentist's offices, a motor vehicle office, and several other shops such as a flower shop, jewelers, and drugstore. The Pentagon also has its own Post Office and consists of 5 different zip codes. Having all these services on site allows the workforce to to conduct their daily business without having to leave the Pentagon reservation. It is also served by a fully equipped gym, medical clinic and library with over 300,000 volumes and 1,700 periodicals.
A Pentagon tour takes about an hour, and is conducted by trained guides from each of the armed services. A highlight of the tour is the Hall of Heroes, containing all the Medal of Honor winners in the nation's history. The tour also visits the 9-11 memorial chapel, commemorating the location where American Airlines Flight 77 hit the Pentagon on September 11, 2001. There is also a visit to the Pentagon courtyard, a manicured 5-acre park containing the Ground Zero cafe, named during the Cold War years, since it was assumed the USSR had nuclear missiles aimed at the center of the courtyard where the cafe stands.
A tour of the Pentagon is a unique opportunity. If you have the chance to visit, it is a fascinating look at how the military headquarters runs, and will definitely be one of the highlights of your visit to our nation's capital.