This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

Go surfing on this urban wave, "hacked" by local surfers.

A fearsome dragon clings to a corner of Munich's city hall.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Old batteries and frog skeletons reside in this lakeside monument to Alessandro Volta.

The secret medieval communication system will whisk your words above the noise of the crowd.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

This 135-year-old weather station studied the effects of the climate on human health.

This statue of a falling man commemorates a teenage martyr of the Hungarian Revolution.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Museum dedicated to the terror regimes of Hungary.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.

Experience what life was like in Ireland during the Viking and medieval ages.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

A man throwing a giant severed hand towers over Antwerp’s main square.