Roman-era ships unearthed...

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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

A modern sliver of architecture in Roma.

An Italian ghost town that fought obscurity, until a mysterious illness brought it to its knees.

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

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

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

A Nesting Doll of Churches.

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.

The final resting place of the poets Shelley and Keats.

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

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

Rome’s legendary peephole vista is also a former Crusader stronghold.

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

Architectureal fantasy quarter of Rome.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

An important landmark in the history of algebraic logic.

An oddly conical beacon perched atop beautiful Irish cliffs.

A tribute to the incredible generosity the Choctaw Nation showed the Irish people during the Great Famine.

Just another ancient, mysterious Irish stone circle.

This Irish museum in a historic 19th century market pays tribute to the glory of butter.

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.