Hear the quietest sound from across the dome.

Giant topiary dog once played a role in a terrorist bomb plot.

A beautiful but toxic fountain of mercury.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

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

These medieval skyscrapers dominate the skyline of this small Tuscan town.

In Florence's great Duomo, a 26 foot fresco honors a mercenary famous for attacking Florence.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Medieval torture techniques with a modern conscience.

Go inside to really appreciate this 500-year-old technological masterpiece.

The ancient tomb acts as a calendar that keeps perfect time.

Behemoth, cannon-like telescope operated by generations of Irish earls.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

France's most famous cemetery, with some of its most curious tombs.

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

Historic medieval fortified city in southwest France.

Macabre astrological automaton clock dating to the late 1400s.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

A small but immensely extravagant palace built by the "Night King."

Tiny castle in the middle of the Rhine made you pay to pass.

A German apartment building hosting as many trees as human occupants.

The footprint of a frustrated devil in Munich's Cathedral.

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

Legendary site where an evil bishop was devoured by rodents.