Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

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

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

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

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

Rome's ancient Etruscan rival, now a park full of ruins.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

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

Richard Luke Concanen never set foot on American soil.

The sacristy of this church contains remains and relics of members of the Aragonese royal family.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

An unusual "skull with ears" sits in the crypt of this small church tucked away at the end of a narrow alley.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

The walls and streets of the ancient city are peppered with penises.

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

This monumental fountain has moved around the city multiple times.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

An exquisite Baroque church in Vienna's old town.