The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

A preserved college lock-up that recalls a clubhouse approach to discipline.

Cold war icon and onetime "hole" in the iron curtain.

A restaurant and observation deck built in a unique broadcasting antenna.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The most visited, and possibly most controversial, museum in Germany.

This ancient theater was once the home of fierce gladiatorial battles.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

Former hunting lodge of a duke who was an avid collector of impressionist works.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

This bridge was constructed from the rubble of the infamous Bastille.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Historic medieval fortified city in southwest France.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.