A Byzantine church containing the holy remnants of three saints sits atop the site of an ancient temple.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

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

Memorials at a Florence railway station remember the citizens who were deported from Italy and sent to extermination camps.

Art and armour fill every inch of this rich kid's Italian villa.

A medieval weapon rumored to have been used by the brilliant poet himself.

The graveyard is filled with beautiful funerary art and boasts breathtaking views of Florence.

Secret refuge and museum of the Duke of Florence.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

On an island south of Iceland, a large volcanic rock formation resembles an elephant.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This rusting remnant of the local herring industry is being given a second life.

This remote eatery and museum is preserved as a time capsule of a small Icelandic fishing town.

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

The largest medical and anatomical collection in France lies hidden from the public.

The celebrated eyesore created by starry-eyed sweethearts.

A museum dedicated to one of Paris’s most famous residents, tucked into a corner of one of the city’s most famous squares.

A simple plaque on the facade is the only reminder that the treaty ending the American Revolution was signed inside.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.