One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

This natural marble cave is one of only five national monuments in Oregon.

This Oregon farm is dedicated to teaching people the professional art of tree climbing.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Odd outsider art installations surround a Gold Rush-era ghost town.

This abandoned prison castle has become an imposing gallery of graffiti art.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

A religious-themed park filled with folk art to bring biblical stories to life that fell into disrepair and now being restored.

One man's ambition created this psychedelic log home.

This abandoned amusement park was built on a site with a dark history.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

Despite being burnt down multiple times, the ruins of this South Carolina church are still standing.

This fairy tale-themed amusement park is now abandoned, and childhood metaphors abound.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Tucked away on an empty wooded lot in suburban Oklahoma City lie the remnants of an abandoned circus camp.

An abandoned relic of the city's failed experiment with below ground transit.

A crumbling hospital from the 1850s on Roosevelt Island.