Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A brutalist gem towering over the heart of Milan.

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

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

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

A statue representing a lost Roman profession that was vandalized for centuries.

This poignant art installation raises awareness of violence against women.

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

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

Known as the "Finger of God," a dramatic rock formation resembles a divine hand extending towards the heavens.

One of the last designs from architect Oscar Niemeyer.

Museum precariously perched on a massive yellow pillar.

Solitary monument dedicated to the beauty of nature.

The gorgeous murals at this open-air museum form the largest street art collective in Chile.