The Vatican's secret porn-festooned bathroom was painted in erotic murals by one of the greatest artists of the Renaissance.

The facade of this 16th-century building is decorated with carvings of 300 seashells.

A small house in Tazones, completely covered in shells.

The largest salt farm in the Canary Islands is located at the foot of an active volcano.

This Roman arena once played host to bloody gladiatorial battles.

This enormous censer uses a pulley system installed over 400 years ago.

This mansion oasis contains gardens, sculptures, and fountains just off the busy Plaça Kennedy in Sant Gervasi.

The unexpectedly beloved remnants of a controversial thermal power plant.

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

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

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

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

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

Barcelona's only remaining tram system takes riders to the Tibidabo funicular.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

Volcanic rocks ground down into sand make this Spanish beach as black as night.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

Stunning Roman aqueduct used for 1900 years and still standing.

A once-secret library of Freemason history in Catalonia.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

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

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

A temple to modernity, tucked away amid Barcelona's more well known museums.