This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

An 18th-century post box used to alert the church of sick and ailing foreign pilgrims.

These hut foundations are believed to be the residence of Romulus, founder of Rome.

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

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

This curious, round temple is the oldest still-standing marble building in Rome.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This statue is the only female representation of Rome's "talking statues."

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

This is the oldest Roman-made bridge in the city still existing in its original state.

A secret hatch containing two parchments was discovered in this statue over 40 years after its installation.

A 16th-century horror show built in a lovely Italian garden.

What appears to be an ancient Roman temple is actually a Catholic church.

This unique house, the only one of its kind in Brooklyn, was built as part of a real estate developer's showcase.

One of only two remaining Victorian-era greenhouses in New York.

A way to take your secrets to someone else's grave.

A mass grave for victims of one of the city’s worst fires.

Records of the dead describe the myriad odd ways people used to die.

After traveling the world, the last remaining fully-rigged three masted iron-hulled cargo ship in the world found its home in New York.

An experimental, community court opened in 2000 takes a new approach to youth offenders in south Brooklyn.

This former Norwegian sailor's church is slowly being taken over by ramshackle robot musicians.

Where infamous mobster and leader of Murder Inc. Albert Anastasia made his home.

Retribution for death of infamous mob boss Franie Yale was a case of mistaken identity.