10 Things You Probably Didn’t Know About the Pentagon

By Claudette Roulo,U.S. Department of Defense

1) Why is the Pentagon, you know, a pentagon?
The land the Pentagon was first planned to go on was bordered on five sides by roads, so the architects designed a five-sided building. President Franklin Delano Roosevelt was worried putting the building at that location would interfere with the view of Washington from Arlington Cemetery, so he chose to move it to its present location, but he kept the five-sided design.

2) Sept. 11 has a double significance for the Pentagon.
Builders broke ground for the Pentagon on Sept. 11, 1941, exactly 60 years before the Sept. 11, 2001, terrorist attacks.

3) The Pentagon is big. Reallllly big.

It’s the world’s largest low-rise office building. The entire U.S. Capitol building could fit inside any of the building’s five wedges. It has 6,500,000 square feet of office space (three times the floor space in the Empire State Building!), 7,754 windows and 17 1/2 miles of corridors. Yet, its spoke-and-ring design means it takes only about 7 minutes to walk between the furthest two points in the building.

4) The builders were frugal with their materials.
During construction, the builders were able to conserve enough steel to build a battleship. And the 689,000 tons of sand and gravel used to make the building’s reinforced concrete – including 41,000 concrete pilings – came from the nearby Potomac River. 

5) Until 2011, there was only one passenger elevator in the Pentagon. And it was reserved for the defense secretary.
A 17-year-long renovation project that finished in 2011 saw 70 passenger elevators installed in the building. Until then, people who couldn’t use stairs used long ramps to move between floors. The ramps are still there, but the rumors of office chair races are greatly exaggerated.

6) That renovation project? It probably saved thousands of lives.