One of the largest underground systems runs under Canada's largest urban center.

New Orleans' famous cemetery, located on the site of a former race track.

The site of a tragic massacre that spawned a multimedia franchise.

In which a local geological marvel becomes a quaint roadside attraction.

Hear the quietest sound from across the dome.

Pop culture has helped to keep this iconic British building from being destroyed.

A castle built for love, and abandoned due to heartbreak.

Semi-precious Blue John stones have been mined in this cavern system for centuries.

One man's desire to transcend art led to the construction of this outsider chapel.

Home to the most complete dodo remains known - one head, and one foot.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

This medieval church tower has maintained its clockworks since the 16th century.

Canada's largest graveyard boasts a lot of noteworthy artifacts as well as its own computerized mapping service.

Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

The first archaeological site discovered by aerial photography.

The final resting place to 300 Victorian-era pets hides inside the city park.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

This legendary city has been a tourist attraction for centuries.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

The oldest working mechanical clock in the world.

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.

Museum design and public transportation meet in this unique Russian train car.