Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

2300-year-old Roman road connecting the empire.

This quiet, unassuming spot in Budapest was the birthplace of the bloody 1956 Hungarian Revolution.

Museum dedicated to the terror regimes of Hungary.

One man's personal collection of KGB memorabilia is presented along with his strange viewpoint.

Looming communist pillar with a Czech twist.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

The great Danube river starts here.

A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

Tiny memorials honor individual victims of the Holocaust.

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

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Metro station with a claim to rock n' roll fame.

For centuries, Germans have been dancing in trees.

A stairway to heaven, or to nowhere at all.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

This beautiful 19th-century temple stands atop the ruins of its predecessor.

A whimsical art tower at a Bavarian brewery includes a grotto for its mythical beer-brewing dwarves.

A serious museum dedicated to two German comedians.

This century-old cinema house has a marquee that has been hand painted by a single man for over 25 years.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

This neon landmark has been posing this deadpan question to follicly-challenged Dubliners for over 50 years.

The ghost town where the villagers refuse to leave.