The Pentagon
It has a total floor area of 6,500,000 sq ft (604,000 m2). Offices are 3,700,000 sq ft (344,000 m2). Approximately 25,000 military and civilian employees 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  of corridors. The Pentagon includes a five-acre (20,000 m2) central plaza, which is shaped like a pentagon.