This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

This automated sculpture of two men peeing will spell out text messages with their micturition.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Macabre astrological automaton clock dating to the late 1400s.

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

2300-year-old Roman road connecting the empire.

Rome’s legendary 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.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."