This grand gate once marked the entrance to a military barracks.

Once a resting spot for King Fernando VII.

A neighborhood represented by an apparent geocentric and flat-earth model of the Solar System is hidden in the subway of Madrid.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

Another of California's unused Cold War missile defense complexes has become a graffiti gallery.

This giant shopping mall still holds signs of its automotive past.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

The giant pair of sexy legs sticking out the window of this costume store have become its main draw.

Medical and zoological curiosities for sale.

This shop specializes in oddities and Victorian-inspired wonders.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

A giant chess set, minus the psychedelic drug trip.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

San Francisco Bay's ghost town.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

An "anarchical" no man's land, complete with garbage sculptures and a hobo-run "Landfillian Library."

San Francisco's newly reopened hands-on science museum.

A man-made island in scenic San Francisco Bay.