TL;DR from Atlas Obscura:
One of the largest free-standing structures ever built, this dirigible hangar is now just a giant skeleton.
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.
According to Wikipedia: In May 2016, Google announced that it is prepared to begin testing different techniques to remove the toxic chemicals from the hangar. In May 2017, it was announced that the restoration of the hangar would be completed in 2025
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