A botanically themed auditorium blooms within the world’s last operating double-decker theater.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

A spiritual retreat in the heart of Los Angeles offers stunning gardens and a labyrinth to lose yourself in.

Rare recess caves fill this unbelievably beautiful Ohio park.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A colorful architectural gem in Seattle's uniquely modern Central Library.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Less a museum than a bizarre fantasy world created by artists and engineers.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

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

Tubing through a cave lit with glowworms is a magical underground experience.

See massive fossils that are over 200 million years old in northeastern Arizona.

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

One man's vast collection of artifacts and ephemera from matchbooks and postcards to vintage neon signs and cars.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

An abandoned stretch of highway, deteriorating next to the operational one.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

These eerie outliers of the lightning bug family glow a mysterious blue color.

Rebuilt remains of a temple to Roman god Mithras.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

More gold than anywhere else, ever.

A modernist landscape of water and sci-fi concrete.