This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This building displays the scars of the “Dekemvriana,” a dark time in modern Greek history.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

These ancient ruins hide in plain sight next to a dessert shop.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

The site where hundreds of Greeks were tortured by the Nazi secret police is now a cosmetics store.

This abandoned shopping arcade has new life as an art installation.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

This striking sculpture of Icarus honors Greece's fallen flyers.

A hospital where antique dolls are given new life.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

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

A forgotten "city of water" underneath the famous Trevi district.

Rome is now home to a stunning food museum and library.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

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

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

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

A spherical "micro-nation" in the heart of Vienna.

Op-art architecture designed for happiness.

Journey through a mesmerizing array of board games inside this museum.