Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

There has been an astronomical clock on this spot since the 14th century.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

This bunker in northern France was built by Nazi German forces with the intention of launching up to 50 V2 rockets at London each day.

Ancient paintings known as the "Sistine Chapel of Cave Art."

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

The world's tallest bridge is also possibly the most elegant.

Mountain where Jesus was first tempted by the Devil.

Saint Joseph was said to heal the deaf and blind, but it was a much smaller miracle that got him canonized.

Turntable anonymously received orphans, alms, and groceries.

This semi-secret storybook hedge maze is also the oldest garden in the city.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

On the wall of this medieval square, a symbol of the Spanish Inquisition.

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

This fountain was designed to honor the man who helped bring water to Barcelona.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

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

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

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.