The blowhole bursts spectacularly right next to the buildings in a medieval seaside town.

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

This 19th-century fountain's namesake animal isn't what you think it is.

Giant topiary dog once played a role in a terrorist bomb plot.

Historic medieval fortified city in southwest France.

There is a strange little carving of a person seemingly crushed by a pillar behind the remains of St. Thomas Aquinas.

This Bordeaux parking garage has 712 indoor spaces, and one outdoor.

The world's largest reflecting pool is just two centimeters deep.

A beautiful little museum hidden away in the heart of Barcelona holds a treasure trove of Ancient Egyptian artifacts

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

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

This influential Renaissance-era library was once the haunt of kings and monks.

The Roman city was the birthplace of various emperors and is home to one of the empire's most impressive architectural feats.

A well-restored ancient archaeology site gives a real feel for life during the Roman age.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

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

Geological storytelling.

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

A reproduction of the famous prehistoric cave paintings is hidden underground at the National Archaeological Museum.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

An early 20th-century bullring converted into a modern shopping center.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

An ancient Roman theatre restored to its former glory in the Spanish city of Cartegena.