17th century streets hidden under Edinburgh were once a breeding ground for the black death.

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.

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

The taxidermied remains of a once-great parrot.

Giant, friendly pelicans in Central London, the most unlikely of places.

A Civil War Museum with some notable medical antiques.

Home to items never before seen by the public.

The United States Capitol's former columns still stand.

Astounding collection of coin-operated games and automata.

Trade in that pesky human soul for cold-hard circuits.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

World's largest Christmas store.

Former self-sufficient mental institution now a planned community.

A Beaux-Arts triumph set to become Ford's innovation campus

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

A stratovolcano located in the south of Iceland, with a long history of charted activity and a rich mythology attached.

This elegant arc of a waterfall marks a religious turning point.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

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