The unexpectedly beloved remnants of a controversial thermal power plant.

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

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

One of Europe's largest supercomputers is housed inside of a disused chapel.

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

Mountain where Jesus was first tempted by the Devil.