The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

The 3.8 billion-year-old rock proves that tectonic plates may have been shifting longer than we thought.

A lake in the middle of the tundra of Quebec is said to be the purest freshwater lake on Earth.

This Maine bridge may be the last wire-supported bridge of its type in the world.

Nearly 40 miles and 1,000 years of limestone mines under Denmark.

This Danish castle is supposedly haunted by a woman too independent to not be a witch.

A collection of noses tucked inside an art museum reveals how times have changed.

The largest bottled beer collection in the world holds over 22,000 unique beer bottles.

A perfectly circular stronghold constructed in the 10th century is now a nucleus of Viking culture housing a museum, village, and reenactment of an epic Viking battle.

A museum dedicated to the silliest fruit.

This German museum devoted to the simple wonders of salt is actually built over an old saltworks.

An intricate and amazing house built by architect Karl Junker.

A model memorial to the original Odin Tower, the second highest tower in Europe before it was sabotaged by Danish Nazis.

This one-man homegrown eatery may be the world's most exclusive restaurant with its five-year waiting list.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

All of Chicago's wood-paved streets are long gone but two alleys remain.

Years of archaeology, just chillin' by the water cooler.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

Nuclear reactor created the plutonium used on Nagasaki.

This angular Dwarven tunnel cuts through a mountainside in Glacier National Park.

See the computer’s history revealed over the course of 20,000 years.

A classic gold rush hotel can be expected to pick up some ghosts along the way, and the Golden North is no exception.

One woman's dream became a train hotel in her backyard.