The Pentagon by Daniela Escudero

The Pentagon (Arlington Country, Virginia) is the headquarter of the United States' Department of Defense. As a symbol of the U.S military, the phrase The Pentagon is often used to refer to that.
The building was designed by American architect George Bergstrom and built by contractor John McShain.
The Pentagon is the world's largest office building, with about 6,500,000 sq ft (600,000 m²) of space, of which 3,700,000 sq ft (340,000 m²) are used as offices. Some 23,000 military and civilian employees, and another 3,000 non-defense support personnel work in the Pentagon. It has five sides, five floors above ground, two basement levels, and five ring corridors per floor with a total of 17.5 mi (28.2 km) of corridors. The central five-acre (20,000 m²) pentagonal plaza is nicknamed "ground zero" on the presumption that it would be a prime target in a nuclear war.