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

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

This giant middle finger statue sends an unambiguous message to Italy's bankers.

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

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

A brutalist gem towering over the heart of Milan.

This poignant art installation raises awareness of violence against women.

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

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

Baroque celebration of the end of the Great Plague of Vienna.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The celebrated eyesore created by starry-eyed sweethearts.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A much-loved sculpture depicting the hero of a 1956 anti-Soviet uprising.

From cartoon characters to tiny tanks, a guerilla sculptor's little bronze statues are hidden throughout the city of Budapest.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

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

A diminutive statue that was inspired by the sculptor's own daughter.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

The metal leaves on this tree are engraved with the names of Holocaust victims.

Structure built from the skulls of vanquished foes.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.