Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Quite simply the largest tree in the world (by volume).

A wall of chewing gum moonlights as collective art.

San Diego's most historic and haunted home.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

This expansive bridge in the Canadian wilderness was originally just built for friends.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A museum dedicated to the history and exploration of both popular music and science fiction.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

Home to the "Circus" trees created by Axel Erlandson.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

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

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

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

Canyon walls shrouded in ferns.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A hotel and restaurant serving as the mecca of kitsch.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.