A hidden three-foot-wide house separates these two regal churches.

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

This statue took 60 years to complete.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.

A plaque marks the site directly below the mid-air detonation of the atomic bomb over Hiroshima.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

Christ's blood allegedly preserved in a Belgian town.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

A medieval setting reimagined into a unique art alley.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

The hallucinogenic center of the ancient world.

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

See no evil, hear no evil, speak no evil.

Just across from the "Last Supper" painting is the famous painter's vineyard, a gift received for creating the masterpiece.

A herd of 150 bison live on California's Santa Catalina Island and are at the heart of an ongoing debate between environmental protection and economic expansion.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

More than 450 years ago, an Italian nun became the first woman to paint the iconic subject.

Experience this Iron Age village the way that its original residents would have.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

In the world's oldest university is a stunning 17th century anatomical theater carved from spruce.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.