This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

A collection of objects supposedly singed by the hands of souls in purgatory.

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

2300-year-old Roman road connecting the empire.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

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

The now-abandoned Fascist summer colony served a dark purpose during World War II.

A sunken idol welcomes parishioners to Davy Jones' Locker.

The bomb-ravaged remains of of a colossal Neptune.

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

Abandoned waterpark turned counter-culture mecca.

Wonderland replication in progress by one persistent man.

Famed architect Antoni Gaudi built this generous thank you gift to a friendly host who housed him during a job.

A Romanesque tower appears when water levels drop.

An architect transformed this abandoned cement factory into his castle-like workshop.

Mountain where Jesus was first tempted by the Devil.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Week-long block party becomes a competition for the best decorated street.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

A once-secret library of Freemason history in Catalonia.

Turntable anonymously received orphans, alms, and groceries.

Beautiful views and Roman-style statues on the Italian coast.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.