A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

This five-star hotel was originally a swanky parking garage.

This massive blockhead sculpture hides an entire library.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This strange statue features a bust of the famous composer plopped atop a woman's body.

This grisly effigy displays an early Christian martyr who was skinned alive and beheaded.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

This statue celebrating everyday life in Dublin has a few unsavory nicknames.

This massive monument has been telling the time for 150 years—at a slight angle.

Northern Ireland's Brobdingnagian stepping stones.

These murals stand as reminders to the troubled history of this Northern Ireland city.

Inside this Krakow church, an explosion of psychedelic color.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This outdoor museum harkens back to the height of the gold rush.

Equipped with thousands of LED lights, this geodesic dome-shaped stadium is an engineering delight.

CERN's beautiful, bending sculpture is a tribute to the spread of knowledge.

Florentine Renaissance style building in Switzerland, home to the world's largest taxidermy Great White Shark.

A constellation of golden cobblestones shows the names of local children born under a full moon.