A seemingly endless landscape of pure salt stretches far across Bolivia.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

Stunning wetlands ablaze with pink lotus flowers.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

Hidden beneath the streets of London is a secret subway that only carried mail.

Enormous lake at the bottom of a unique cave system.

This faux-seedy Japanese arcade is made up to look like a maze of alleys straight out of a cyberpunk dystopia.

A 140-year-old castle with underground caves hidden in San Francisco.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

An enormous, inside-out glass globe built in 1935.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

An Australian lake whose pink hue defies scientific explanation.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

A swing to dangle you off the very edge.

A massive underwater sinkhole made famous by Jacques Cousteau.

Hot springs monkey spa in the middle of Hell's Valley.

A 16th-century horror show built in a lovely Italian garden.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

A fiery crater has been burning in the Karakum Desert since 1971.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

An ancient capital city that dates back 3,000 years old and harbors many surprises.