Rome's first modern graffito is all that is left of a peaceful protest from the 1970s.

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

Twelve hundred stone carvings guard this off-the-beaten-path Buddhist temple.

On Japan's Tashirojima Island, cats are king.

More than 100 Hindu temples are slowly being swallowed by the forest.

The history of radiation is on safe display at the foot of a radiation science laboratory.

A modern-day Lascaux cave underneath Paris.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

A medieval military street hidden beneath a charming French fishing village.

Artist's eccentric property excessively decorated with found objects and work of his own.

A unique underground structure dating back to the 1st century BC.

This tiny cafe is one of the last meeting places of its kind, allowing revolutionaries a place to plot.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

Series of underground houses inhabited continuously for centuries.

One of the greatest maze designer’s greatest mazes.

Walk through living pictures and music in the Cathedral of Images.

Hundreds of hidden passageways weave through the old quarters of Lyon.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

Antique cinematography artifacts fill this museum dedicated to the inventors of the moving picture.

One of the most powerful religious centers in the Middle Ages, dubbed the founder of Western monasticism.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.