This cafe offers a curated collection of treats and tipples made by monks and nuns.

A temple to modernity, tucked away amid Barcelona's more well known museums.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Turntable anonymously received orphans, alms, and groceries.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

Mountain where Jesus was first tempted by the Devil.

A beautiful but toxic fountain of mercury.

This semi-secret storybook hedge maze is also the oldest garden in the city.

An 18th century fountain and two columns are all that remains of Rome's forgotten river harbor.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

This ancient trail climbs the mountain where a Latin League cult worshipped Jupiter, its main deity.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

This park on the outskirts of Rome boasts two ancient Roman aqueducts and a medieval tower.

Ancient ruins hidden underneath a modern luxury hotel.

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

One of the most important yet well-hidden museums dedicated to the history of medicine.

The mystic whose incorrupt corpse still attracts the faithful.

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

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

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

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The underground sanctuary of a mysterious ancient cult.