Hangar One

Located inside the NASA Ames Research Center in Mountain View, California, the massive structure built to manufacture and hold lighter-than-air craft such as zeppelins, known as Hangar One, remains one of the largest freestanding structures in the world, although it is now simply a skeleton of its former self. 

Originally built in 1933, the huge hangar covers eight acres of land and stands almost 200 feet high, and could cover six football fields beneath its canopy. It was created as a housing for the USS Macon, a naval scouting airship that was one of the largest ever created in America and which holds the record (along with its sister ship, the Akron) as being the largest helium airship in the world. Hangar One was built with an aerodynamic design so that the winds buffeting the structure could simply pass around it. The ship could enter and leave the giant hanger via a set of 200-ton clamshell doors that would open out to help reduce the wind shear on the Macon as it entered and exited.

After the Macon was lost in 1935, the hangar continued to be used to store and work on aircraft, but given its unwieldy size, it was eventually deemed unsustainable and by the 1990s the massive structure was essentially left empty. Plans to turn the hangar into a science center were scuttled in the early 2000s when hazardous chemicals were found to have been seeping off of the lead paint coating the vast exterior. A number of expensive plans were proposed, including cleaning the exterior or recovering it, but with no one to foot the bill the exterior panels were simply removed in 2010, leaving behind nothing more than a giant metal skeleton.

Today the remains of the structure still stand on the AMES Research grounds. Luckily for the future of the hangar, in 2014 Google agreed to spend $200 million dollars to rehabilitate the site, so that it might remain for the future.