A collection of 20th-century automata, penny arcade games, and musical contraptions.

A mysterious air force base built to resemble a Long Island fishing village.

A miniature train-ride through Slovenia's largest cave system.

A walk through the historic city center, under the streets of Seattle.

42nd story Pyramid shaped penthouse tops Seattle's oldest skyscraper.

Megachurch turned Catholic church comprised of 10,000 glass panes.

The first American department store, and home to the largest operating musical instrument in the world.

Rummage through this sunken ship, but leave your scuba gear at home.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

Concrete strongholds stand guard over the Golden Gate.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A perfect circle of twenty-four mysterious holes dates back to prehistoric time.

Where the embers of the Big Bang were first detected.

'Cause the fence start shaking, the earth was quaking.

Ride the subways of yesteryear.

Historic funicular railway, believed to be the shortest railroad in the world.

"We Seceded Where Others Failed."

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The second oldest continuously operating bar in Louisiana.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Why have you never heard of the second most popular tourist site in New York?