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

It's believed a local adventurer spent 50 years living inside this cave.

This little-known national museum houses over 40,000 works of art from across the world.

17th-century tradition of public weighing is met with boos or cheers depending on the Mayor's weight.

You can spend the night in Dr. Frank-N-Furter's castle.

Once a year, a sandbar rises from the depths just in time for the world's weirdest match.

At this unique farm, you can interact with adorable donkeys and view an ancient dolmen.

The bizarre home and sculpture garden of an eccentric artist.

An isolated village literally built into the crevices and rock formations of a mountain.

An otherworldly art experience.

This centuries-old tower hosts endangered bald ibis mating pairs and looms over a pristine beach.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

One of Europe's oldest yew trees has lived more than 2,000 years.

The atmospheric ruins of a historic church can be found on a hill above the city of Oviedo.

A small house in Tazones, completely covered in shells.

Stormy conditions send jets of seawater bursting through holes in the cliffs.

The remains of an encyclopedic sculpture garden later used as an internment camp.

This enchanting natural park is a magical example of a temperate rainforest in Europe.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

This century-old ruined temple was reborn as "The Church of Skate."

The closed and crumbling Francoist luxury resort for workers is still full of life—for now.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

This museum documents the ancient practice of salt production in Figueira da Foz.

This tower once served as a radar station during the Cold War.