Hikers can still stroll beneath the long conveyer of this abandoned mining facility hidden in a West Virginia river gorge.

After an epic flood washed away its enslavers, this city has been part ghost town, part cultural wildcard for the past three centuries.

Planned as the world’s first zero-carbon city, it had lofty ideals—but is only 5 percent completed and aiming for 50 percent carbon-neutral.

Abandoned hotel with adjacent lake and golf course.

The secret city built by the Manhattan Project.

A small medical museum with a recreated doctor's office.

Explore an early California pioneer's rancho hidden in LA's manufacturing hinterland.

Home to items never before seen by the public.

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

A small sculpture garden that provides a microcosmic representation of California.

This little blue house pokes out over the campus of UC San Diego, seven stories high.

The cobbled together compound of a deceased artist which now serves as a filming location.

This large collection of tiny things revels in the art of fine machinery well made.

This dark, quiet forest on the outskirts of San Diego is dense with rumor and lore.

A museum within a museum, devoted to history's most questionable medical devices.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

One of the few remaining carousels built by master amusement park carver Charles I.D. Looff.

Funhouse of found art and participatory sculpture.

This rare vessel mixed luxury with labor before being converted to a museum and sometimes haunted maze.

17,400 lbs., 12 feet in diameter, and 29 years in the making.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

This whimsical stacked cabin looks like something out of a children's book.

This abandoned secret city is a crumbling wonderland of Soviet ruins.