The deserted remains of a luxury hotel turned hospital ward.

A road that winds through this natural cave is the only way to access the small, appropriately-named village of Cuevas.

This magnificent market stands as a poignant symbol of the suffering caused by the Spanish Civil War.

The highest peak in mainland Spain is said to be the final resting place of a Muslim king.

The surviving remnants of a destroyed medieval church now stand in a public park.

King Carlos IV laid the first stone during construction of this chapel.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

This abandoned gold mine found a second life as a post-apocalyptic film set.

This house covered in small stones was the work of one man over the course of nearly 30 years.

This Art Nouveau gate still stands at the former entrance of a 20th-century Spanish writer's colony.

Rumors and legends of secret Nazi activities surround this eerily remote island mansion.

Meant to resemble a massive tree, the building is the best example of Spanish organicist architecture in Madrid.

An uninhabited village that preserves and documents rural architecture and an endangered way of life.

A 12th century church completely covered in shells.

Inaugurated three times, this tower offers some of the best views of Madrid.

Semi-mystical manmade towers of rocks decorate this rocky seaside.

This architectural oddity is an oasis of green on the outskirts of Valencia.

This Roman arena once played host to bloody gladiatorial battles.

The ruins of an ancient Celtiberian town with incredible rock-cut buildings and a Roman aqueduct.

Abandoned 18th century weapons factory in the Aezkoa Valley.

Sink your spoon into a luscious crema Catalana at this former urban dairy farm.

One of Europe's largest groups of dolmens remains largely off the typical tourist track.

This enchanting green space houses a labyrinth lined with toxic plants.

Not far from Madrid, a set of perfectly preserved trenches date back to the Spanish Civil War.