A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

Tour the sci-fi-esque reality of governmental disease management.

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

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

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

This cemetery features modernist statues as strange as its name.

A beautiful but toxic fountain of mercury.

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