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

This room of wonder is full of relics, from knights in armor to rare works of art.

Among the busts of heroes of the Roman Republic of 1849, there is also a statue of a boy and his dog.

This hermitage celebrates the legend of Emperor Constantine's healing from leprosy.

This basilica is dedicated to two saints, one of which is known more for his famous quote.

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

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

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

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

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.

The fountain marks the area where hundreds of accused witches were burned at the stake.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The world's tallest carillon is located at the top of this skyscraper in Mexico City.

A jewel of the Mexico city skyline now slowly crumbles after surviving an earthquake.

The ruins of the bathhouse used by the ill-fated last Aztec emperor still lie in Chapultepec Park.

This colossal ancient sculpture of the monstrous Aztec rain god has a literally stormy history.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

The only castle in North America to ever house European sovereigns.

The first mechanized factory in Spain is also one of the most significant mints in the history of money.

These "mermaids" that surround a plaza in Segovia are rather sphinx-like.

A curious memento mori hangs in the magnificent Cathedral of Segovia.

A controversial art piece that harkens back to local folklore.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.