This subtle Berkeley paving stone actually marks off a lawless tube of air that extends into space.

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

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

Experience a charming 1930s version of "infotainment."

Flashy signs from Las Vegas’s past find their final resting place at this unusual graveyard.

The second-largest gold nugget in existence, displayed in a Las Vegas casino conveniently named the Golden Nugget.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

Largest Roman Catholic church in North America.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

A place of great reverence for Trekkies everywhere, a hero's future birthplace.

This zombie-themed restaurant stands out in the heart of corn country.

A floating museum that was sunk by a flood and left to rot in the tides.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Fresh wooden posts have been added to ancient holes to recreate a primitive henge clock.

One of the longest water bridges in the world was built over a supposedly haunted swamp in Louisiana.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

The second oldest continuously operating bar in Louisiana.

This symbolic piece of New Orleans architecture is also home to a few ghastly stories.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

Home to items never before seen by the public.