Layout and facilities

The Pentagon building spans 28.7 acres (116,000 m2), and includes an additional 5.1 acres (21,000 m2) as a central courtyard.

Starting with the north side and moving clockwise, its five façade entrances are the Mall Terrace, the River Terrace, the Concourse (or Metro Station), the South Parking, and the Heliport. On the north side of the building, the Mall Entrance, which also features a portico, leads out to a 600-foot-long (180 m) terrace that is used for ceremonies. The River Entrance, which features a portico projecting out twenty feet (6 m), is on the northeast side, overlooking the lagoon and facing Washington. A stepped terrace on the River Entrance leads down to the lagoon; and a landing dock was used until the late 1960s to ferry personnel between Bolling Air Force Base and the Pentagon. The main entrance for visitors is on the southeast side, as are the Pentagon Metro station and the bus station.

There is also a concourse on the southeast side of the second floor of the building, which contains a mini-shopping mall. The south parking lot adjoins the southwest facade, and the west side of the Pentagon faces Washington Boulevard.

The concentric rings are designated from the center out as "A" through "E" (with additional "F" and "G" rings in the basement). "E" Ring offices are the only ones with outside views and are generally occupied by senior officials. Office numbers go clockwise around each of the rings, and have two parts: a nearest-corridor number (1 to 10), followed by a bay number (00 to 99), so office numbers range from 100 to 1099. These corridors radiate out from the central courtyard, with corridor 1 beginning with the Concourse's south end. Each numbered radial corridor intersects with the corresponding numbered group of offices (for example, corridor 5 divides the 500 series office block). There are a number of historical displays in the building, particularly in the "A" and "E" rings.citation needed

Subterranean floors in the Pentagon are lettered "B" for Basement and "M" for Mezzanine. The concourse is on the second floor at the Metro entrance. Above ground floors are numbered 1 to 5. Room numbers are given as the floor, concentric ring, and office number (which is in turn the nearest corridor number followed by the bay number). Thus, office 2B315 is on the second floor, B ring, and nearest to corridor 3 (between corridors 2 and 3). One way to get to this office would be to go to the second floor, get to the A (innermost) ring, go to and take corridor 3, and then turn left on ring B to get to bay 15.

It is possible for a person to walk between any two points in the Pentagon in less than seven minutes. The complex includes eating and exercise facilities, and meditation and prayer rooms.

Just south of the Pentagon are Pentagon City and Crystal City, extensive shopping, business, and high-density residential districts in Arlington. Arlington National Cemetery is to the north. The Pentagon is surrounded by the relatively complex Pentagon road network.

The Pentagon has six Washington, DC, ZIP Codes (despite its location in Virginia): The Secretary of Defense, the Joint Chiefs of Staff, and the four service branches each have their own ZIP Code.

As of July 2020, Pentagon tours were suspended due to the COVID-19 pandemic.