A marvel of Byzantine engineering under the streets of Istanbul.

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

A haven for book enthusiasts across the street from Retiro Park.

An art project designed to encourage people to explore and investigate their surroundings more closely

Eat the ultimate iteration of Portugal's most beloved pastry.

A massive mammoth bone has been on display inside this church since the 18th century.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

See 150 million-year-old dinosaur tracks and bones dating back to the Jurassic period.

At almost 1,000 years old, this is the oldest known door in all of Britain.

Krakow's own version of the Hollywood Walk of Fame.

The first documented commercial gold find in the United States.

The remnants of the base where US Army troops learned how to fight in extreme conditions.

This lonesome Monterey cypress has survived centuries of wind, salt, and at least one attempt at arson.

Despite being one of the most photographed vistas in the Rockies these twin peaks are rightfully known as the "Deadly Bells."

This fully restored synagogue explores the American Jewish experience along the old frontier.

At one time this small mining village was the highest town in America but now it sits abandoned while the mine churns on.

This fallen red oak tree has been transformed into a piece of trailside art.

Once a resting spot for King Fernando VII.

A memorial for public executions that dates back to the 14th century.

A herd of colorfully painted bovine statues can be found in the middle of "cowtown."

A small and quirky museum hidden inside a fence.

Take a hike to this remote, scenic tea stop in the Canadian Rockies.

A royal relic from the time that gambling was accidentally made legal in South Carolina.