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

Saint Borromeo often prayed in this austere crypt during the 16th century.

Artistic tombs, monuments, and a beautiful "Hall of Fame" lurk inside this cemetery.

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

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

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Amsterdam's former hotspot for public executions and dissections.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

Established in 1638 to battle the Black Death, this botanical garden is a treasure trove of rare flora.

This little Greek plateau is home to thousands of rustic, white-sailed windmills.

This abandoned Greek island was the last active leper colony in Europe.

This famous archeological mystery may be an ancient example of movable type.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

The enchanting archway is the only surviving portal into Dublin’s lost medieval wall.

This centuries-old wooden wonder was built in less than a year and is one of Europe's largest timber-framed churches.

This formerly-prosperous Silesian mining town was completely demolished in the late 1960s and early 1970s as an attempt to cover up a secret Soviet uranium mine.

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

A statue in the center of Dublin dedicated to one of their favorite sons of rock & roll.

These gigantic skeletons tower over visitors and provide insight into the creatures that once ruled over Ireland.

The oldest public library in Ireland.

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

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

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.