Mine shafts and hard pastries await visitors at this massive mountain of salt.

Mysterious Spanish catacombs of unknown origins.

This Funeral Hearse Museum represents the finest in cadaver transportation.

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

A lush indoor jungle fills this bustling Madrid transportation hub.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Commonly acknowledged as the only public monument to the Devil himself.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

An architect transformed this abandoned cement factory into his castle-like workshop.

Wonderland replication in progress by one persistent man.

Bacteria and algae give the salty water its bubblegum hue.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

1,001 carved statues of the Buddhist God of Mercy, each with a unique face.

Hanging over one of Japan's "hidden valleys," these vine bridges must be remade every three years.

The magical, mossy forest that inspired Princess Mononoke.

This massive wooden building contains a giant Buddha, healing pillars, and tame deer wandering the grounds.

Once the most densely populated place in the world, this island is now a ghost town.

A beautiful, dense forest in the shadow of Mount Fuji, with a tragic reputation.

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

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.