It is a rare survivor of a World War II early-warning radar station.

To guard against potential invasions, the U.S. Army built "farm" buildings; the cinderblock structures, complete with shingled roofs, and fake windows and dormers, housed an early-warning radar station.

From the air, the sea, and even the road, these buildings appeared to be part of a working farm.

In fact, they housed a diesel generator, electronic equipment, and two 50-caliber anti-aircraft guns.

This is one of 65 that were built all along the western coast of America during World War II.