A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

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

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

A Texas-sized particle collider that was abandoned due to its Texas-sized budget.

The final resting place of a space program monolith.

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

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

On the top floor of an upscale department store stands a lavish restaurant housed in a replica of a luxury French dining car.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

A clear blue swimming hole with hidden caves, still unexplored.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

This woodland architectural installation acts as a camera obscura for the heavens.

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

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

An unrealized dream to wirelessly electrify the entire Earth.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Ride the subways of yesteryear.