People tend to check in during these times:
The Navy built Hangar One at Moffett Field in 1932 for the USS Macon and to serve as the West Coast base for the U.S. lighter-than-air aviation program.
One of the world's largest freestanding structures, covering 8 acres. It is an iconic landmark in the San Francisco Bay area and a part of its early aviation history.
Hangar One used to house dirigibles and blimps pre-WWII.