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

The world's largest wooden structure.

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

A landscape decorated with enormous skull sculptures.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

A Spanish forest is filled with mysterious stone carvings.

This whimsical winery by Antoni Gaudí looks ripped from the pages of a fairytale.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

One of Europe's largest supercomputers is housed inside of a disused chapel.

The morbid items in this small and hidden museum are not for the weak stomached.

At the foot of a waterfall lies a peaceful swimming lagoon and evidence of over 60,000 years of human habitation.

The studio of Catalonia's most famous theatrical designer remains exactly as he left it.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

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

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

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

Wonderland replication in progress by one persistent man.

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

Bacteria and algae give the salty water its bubblegum hue.

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

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

A beautiful but toxic fountain of mercury.