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

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

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

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

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

Turntable anonymously received orphans, alms, and groceries.

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

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

The oldest giants in Catalonia are now displayed in a 14th-century Gothic church.

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

Museum deep in the catacombs of St. Michael the Archangel Church is explored by touch, sound, and smell.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

This massive Brazilian church is built like an angular, technicolor pyramid left by Mayans from the future.

A 125-meter long "tribute to the Brazilian people."

Few other hotels can rival the grandeur of the Castle in the Rockies.

This massive mall has hundreds of shops, an amusement park, and a history of deadly amusement attractions.

Elvis's own personal tropical hideaway.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

This replica of the Greek structure is in the heart of Nashville.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This pun was simply waiting to come to life, and one defense contractor made it so.

At 207 feet, one of the world's longest continuous escalators.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.