The world's largest wooden structure.

A 16th-century Andalusian palace.

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

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

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

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

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

A unique seaside cave where Aleister Crowley faked his own death.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

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

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

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

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

After the owner of this Art Nouveau home died, it was turned into a museum displaying a lifetime dedicated to art.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

This unique architectural wonder is also tied to one of the 20th-century's most renowned writers.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Located in the thermoelectric factory that once powered the entire city, this Portuguese museum is shockingly fascinating.

Feast on buckets of garlicky snails.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.