A fairy tale castle in modern Rome.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

An alchemist's "magic door" stands in the middle of a Roman park.

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

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

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

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

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

A sculpture serving as an homage to Pope John Paul II.

This mountain fissure hides a secret path to a secluded mossy grotto within the rock itself.

A 18th century graveyard and its astonishing cortege of macabre iconography.

A naturally mummified 2,000-year-old man.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

The first green space constructed on an elevated viaduct.

According to fictional Kcymaerxthaereal history, a powerful woman with a voice whose beauty could not be concealed found solace at this site at the Majestic Hotel in Singapore.

A Buddhist theme park brings you a Buddhist version of Hell.

Where commuters walk through remnants of an ancient Greek necropolis.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

Large collection from the 3rd millennium BCE.

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

A sprawling collection of books and manuscripts about ancient Greece that would have put their famed libraries to shame.

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

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

This tin chapel was built by POW's during World War II and is painted to look like something much more grand.