The Pentagon Tours program, under the purview of the Assistant to the Secretary of Defense for Public Affairs, hosts more than 106,000 visitors annually. The tours dynamically highlight the respective missions of the five Armed Services, the Office of the Secretary of Defense and the Joint Staff through a 60-minute presentation that includes a 1.49 mile walk through the building. This walk is punctuated by colorful displays and historic photographs depicting significant moments in military history, including the 9/11 Memorial Chapel. Built in just 16 months, the Pentagon is the world’s largest low-rise office building. It is twice the size of the Merchandise Mart in Chicago, has more than twice the floor space of the Empire State Building, and the U.S. Capitol could fit into any one of its five wedge-shaped sections. It boasts nearly 17 and one half miles of corridor, yet due to the Pentagon’s unique design, movement between any two opposite points takes as little as seven minutes. In addition, there are 19 escalators, 131 stairways, 284 restrooms, 691 water fountains and enough telephone wire in the building to wrap around the world four and one-half times.