Archaeological sites and great food inside the island's largest mangrove forest.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

An enigmatic modern marker left next to a historic Roman site.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

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

The mystic whose incorrupt corpse still attracts the faithful.

Plaques on its facade commemorate the Tiber's most destructive deluges.

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

In the early Roman Empire, people deemed traitors and criminals were tossed to their deaths from this rock.

A massive marble foot is tucked away in a small alley near the Pantheon.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

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

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

This ancient market is often referred to as the oldest shopping mall in the world.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

A Nesting Doll of Churches.

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

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

Its interior is adorned with some of the best examples of early Christian mosaics.

An ancient Egyptian obelisk is now used to commemorate fallen Italian soldiers.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

These red and black houses were awarded to the firefighters who saved their city from an enormous blaze.

This former sugarcane transport tunnel is now a portal to a lovely beach.