A bizarre roadside attraction and the first instance of miniature golf in the world.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

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

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.

A Hawaiian stairway to heaven—that you can't climb.

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

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A hand-built folk art installation covered with messages of God's love.

Site of a former hidden treehouse in New Orleans.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

Naturally formed rock city in Poland.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

Australian Lake set aglow by Noctiluca Scintillans.

Sculpture of a bus made from wrecked passenger cars.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

For a couple of months each year this Swedish city turns into a festive neon phantasmagoria.

Once the nail factory shut its doors, this Swedish factory town was abandoned, leaving behind a modern ghost town.

The remnants of a record-setting industrial bucket system can still be found dotting the Swedish countryside.

The internet as provided by a James Bond villain.

Sweden's oldest animated sign is still lighting up the skyline today.

A hidden bathhouse in one of Stockholm's oldest and busiest neighborhoods is open to anyone who can find it.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.