The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

The ancient latrines of the Greeks, in all their public glory.

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

What once sat in the world’s spotlight is today a largely disused ghost complex.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

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

Where commuters walk through remnants of an ancient Greek necropolis.

This legendary city has been a tourist attraction for centuries.

The hallucinogenic center of the ancient world.

The grave of the iconic Kentucky Fried Chicken mascot features a bust of the man behind the goatee.

Visit the monolithic tomb of America's most famous general.

The famous author's cottage hideaway.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

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

The former hotel where Tesla invented the radio.

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

Unrepaired walls from a 1920 anarchist bomb attack.

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

Avoid gangster interaction while window-shopping.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.