This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

Architectural monsters are devouring this palace's every door and window.

The yawning maw of this pagan visage is said to bite off the hands of liars.

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 sculpture serving as an homage to Pope John Paul II.

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

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

This Polish cave has housed a dragon, a brothel, and an enduring legend.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

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