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

The artist James Turrell is repurposing an extinct volcano crater as an observatory to experience the cosmos.

Dramatic river bend surrounds a natural red-rocked pedestal.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A self-built castle made by a mysterious man.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Rippling sand dunes frozen in the Arizona rock.

Most-visited and most-photographed slot canyon in the American Southwest.

This 19th century train workshop is a treasure trove of railroad history.

One of the last remaining Carpenter Gothic churches is situated on a wildflower conservatory overlooking the bay.

Housed in a memorial lighthouse, this museum relays the history of surfing, beginning with the antics of royal Hawaiian teenagers.

For roadside fast food, pull over at the giant orange.

A bronze tribute to a legendary Californian, the self-proclaimed "Emperor of the United States."

This contorting sculpture is the tallest in San Francisco.

A quiet nook at the top of a little-known hilltop park named after California's first poet laureate.

A garden oasis filled with flowers mentioned in the works of William Shakespeare.

At the base of the Golden Gate Bridge, a small sign basically begs for a high-five.

A mesmerizing disco ball-like sculpture along the Sacramento River Walk.

Before it was abandoned and left to rust alongside the road, this riverboat starred in a John Wayne movie.

A gap in the concrete has been transformed into a miniature playground for the mind.

A unique piece of graffiti offers a little slice of local history and mystery.

One of the most elaborate displays of Jellyfish is on display at the aquarium.

Two mammoth statues inspired by equally tall tales lure tourists to this roadside attraction.