The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

A portion of the old Pirates stadium over which a defining home run once flew still stands even after the rest of the stadium was torn down.

Mutant vegetables, transgenic mosquitos, and atomic rodents span the walls of this one-of-a-kind museum.

This eccentric mansion museum holds a impressive collection of rare and automatic instruments.

This icon of the Atomic Age now lays dormant.

A world-class theater sits hidden in this remote town in West Iceland.

What was meant to be a temporary exhibit is now a permanent fixture at the St. Louis Zoo filled with beautiful birds.

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

A science fiction-inspired apartment building designed by a famous Spanish architect.

A five-square-mile slice of Spain on the Mediterranean coast of North Africa.

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

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

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

Mountain where Jesus was first tempted by the Devil.

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

This cemetery features modernist statues as strange as its name.

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

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

This restaurant preserves and serves lesser-known and regional Nepali food.

Train cars and railroad artifacts abound at this restaurant devoted to railway history.

You can get anything you want at the former site of the restaurant immortalized by Arlo Guthrie.

A painfully obvious spy house sits right across the street from the Russian Embassy.

Originally built as a promotional giveaway, this suburban house was designed to be an IRL version of the Simpson home.