A self-built castle made by a mysterious man.

The state's only comprehensive museum dedicated to the mineral that defined its history and economy.

Tucked away behind an unassuming set of shops is a must-see series of stunning murals.

An inconspicuous footbridge beloved by San Diego locals.

The oldest standing structure in downtown San Diego.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A tunnel with windows, so you don't miss out on the impressive views.

This little replica of Lady Liberty provides a bit of NYC in a Japanese city.

Once a black market electronics marketplace, now an otaku shopper's paradise.

A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

A stone pillar marking the location of the westernmost battle of the American Civil War only honors one side of the conflict.

Open since 1938, this diner has kept its fountain, malt machine, and all the gum that greasers left beneath its counter.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Once the product of an inexplicable gold strike, this ghost town is now home to one man and his love of classic machines.

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

There are owls with glowing eyes in Herald Square.

A terrific purveyor of natural history objects and curios.

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

This 19th century jail was mainly used to incarcerate the drunk and disorderly.

A futuristic temple of light uses prisms and rainbows to create an atmosphere of peace.