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

This large, circular tomb is the final resting place of the first emperor of Rome.

2300-year-old Roman road connecting the empire.

The yawning maw of this pagan visage is said to bite off the hands of liars.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

A remnant from the golden age of aviation still in use today, Pan Am's Clipper service took off from this Art Deco gem.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Elevated freight railway turned wildly successful urban park.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

This impressive Boston holy house is the American mecca for Christian scientists.

Millions of numbers carved in glass represent the tattoos forced upon victims.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

The site of Paul Revere's historic two lantern warning.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

This little-known wall in Southampton stands as one of the most unique and personal monuments to D-Day.

In 1977, an eccentric book lover formed a micronation for book lovers.

Dedicated to the five postal workers who died aboard the doomed ocean liner, this plaque was made from a spare propeller from the Titanic.

Montmartre's sole surviving windmill became an iconic landmark for 19th-century painters, artists, and bohemians.

A glamorous hotel that once accommodated French resistance fighters and concentration camp survivors.

The video game-themed street art first popped up in the French city.