From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

Two thousand artifacts from around the world collected by one woman who loved to travel.

The most famous location in China was home to whole dynasties worth of imperial rulers.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

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

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

A small pack of an ancient, hairless breed of dog once believed to guide souls through the underworld lives on its grounds.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

This extraordinary art museum is like a secret world on the edge of Mexico City.

This old-school café is famous for serving coffee, chilaquiles, and the Cuban Revolution.

The ruins of an ancient temple to the Aztec wind god discovered in the middle of a metro station.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

Mexico City's largest market contains a Willy Wonka-esque wonderland.

Explore the atmospheric ruins of an abandoned convent in the dense forests of Mexico's first national park.

The only castle in North America to ever house European sovereigns.

66,000 pieces of art, donated by one of the world's richest men.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

Part bookstore, part café, and part forest.