A look inside the Pentagon, the heart of the US military

Located in Arlington, Virginia, just across the Potomac River from Washington, DC, the Pentagon has served as the epicenter of the US military, housing the Department of Defense, the Army, the Navy, and the Air Force, since the 1940s. (Photo By Bill Clark/CQ-Roll Call, Inc via Getty Images)

The Pentagon, as the headquarters of the US Department of Defense, also serves as a primary headquarters for the Army, Navy, and Air Force. The Pentagon is mainly used for bureaucratic operations, with about half of its floor space being occupied by offices. Nearly 30,000 civilian and military personnel work in the Pentagon, which is the world’s largest office building. The Pentagon also contains multiple chain stores and amenities, such as a food court, a federal credit union, a CVS pharmacy, a Starbucks, and a Subway restaurant. (Rich Clement/Bloomberg via Getty Images)

The Pentagon’s Hall of Heroes, first opened in 1968, is a space used to commemorate about 3,500 Medal of Honor recipients in the Army, Sea Service, and the Air Force. Located on the second floor on the Pentagon’s main concourse, the Hall of Heroes is also used as a primary hosting venue for events, which include speeches, promotions, retirements, and other ceremonies. (Photo by Cheriss May/NurPhoto via Getty Images)