The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

A living art gallery painted on a canvas of Monterey pine trees.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

Medieval ruins nestled within a breathtaking swath of Spanish nature.

The deserted remains of a luxury hotel turned hospital ward.

A landscape decorated with enormous skull sculptures.

Sanctuary on a ridge near an ancient shrine to a "Black Madonna" built by the founder of Opus Dei.

A series of recreated fortifications mark George Orwell's path through the Spanish Civil War.

A charming Spanish village sits atop this natural limestone overpass.

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

A Spanish town built into the cliffs.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

A model solar system adds a celestial touch to this suburban park.

Whether they are bulls or pigs, these ancient animal sculptures are fascinating relics.

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

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

This small Spanish village is home to dozens of public paintings meant to trick the eye.

A 12th century church completely covered in shells.

This abandoned naval battery stood at the ready as recently as the 1980s.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Launch site for nuclear war against Western Europe.

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

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