The New York Times:

The circular building housing Apple’s headquarters in Silicon Valley is so big, it’s nearly a mile in circumference. So it’s hard to fathom that it is not actually attached to the ground.

The spaceship, as the building is often called, is a mammoth example of a technology that reduces earthquake shaking by as much as 80 percent.

The building is one of a relatively small number in the United States that use so-called base-isolation technology.

It looks like under the Apple spaceship campus is almost as interesting as what’s above ground.