This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

This historic train station has been converted to a locomotive themed hotel.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

The US Navy's only submarine museum is also home to the world's first nuclear submarine.

A daily replay of the experiment that proved the rotation of the Earth.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

A wall of chewing gum moonlights as collective art.

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

Prone to disastrous fires, the city of San Francisco has the Guardian, a fireboat gifted by residents, to watch over them from the bay.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A huge musical instrument played by the ocean.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

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

A former waterfront market is now in the center of town due to some interesting Boston engineering.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

The site of Paul Revere's historic two lantern warning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

The final resting place of many of New Jersey's most famous residents, including U.S. history's most in-vogue antagonist, Aaron Burr.

A bronze monument to the infamous radio broadcast in the real New Jersey town where the fictional Martians crash-landed.

Seven golden statues rise into the sky from sculptor Victor Victori's New Jersey front lawn.