This huge dam across the Colorado River caused an armed standoff between two U.S. states.

Crumbling pink walls and murder memorials preserve the pioneer history of Joshua Tree.

A lighthouse built to save lives that took quite a few with its treacherous location.

This historic steamboat is scuttled just a few hundred feet from where it was built over a hundred years ago.

The first North American landing spot for James Cook on his third voyage of discovery in the Pacific.

This great stone guardian of the forest is a relic from the land's volatile volcanic past.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

A sprawling cave network created by a lone lava tube.

A sculpture of a salmon swimming through a brick building.

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

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

At this 1940s-era neighborhood favorite, you can still drink a cherry phosphate.

Puzzling...this tree looks like an assemblage of dismembered monkey limbs.

This hidden fire lookout offers spectacular views of Sequoia National Park.

A fire lookout atop a glacial pinnacle is reached by climbing three vertiginous flights of stairs.

The viewpoint for this attractive, off-the-beaten-path waterfall is reached by a paved, wheelchair-accessible trail.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

Curiously, this large sporting goods store features 14 wax representations of American presidents.

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

The overgrown ruins of a once thriving World War I-era copper mine.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

A volcanic cone that formed over 600 years ago.

One of the coolest murals in Minneapolis.

Sleepy Minneapolis block beats Guinness Record for most churches on one city block.