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

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

The eroded core of an ancient volcano is now accessible by a short hike.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

The cinder cone volcano with a less than complimentary name.

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

A living snapshot of a different time in America is preserved and maintained by a community of volunteers.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

This collection of Wild West movie memorabilia also claims to hold some secrets of the Lost Dutchman's mine.

This Route 66 classic sports a giant fiberglass rabbit that you can ride.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A motel dedicated to Southwestern nostalgia.

The story of Two Guns, Arizona could easily be described as a Shakespearian tragedy on Route 66.

One of the largest, oldest, darkest, quietest motel rooms in the world.

A Saint Nicholas-themed ghost town in the Mojave desert.

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

A reproduction of earth's many biomes.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

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

A sharp bend in a dramatic river canyon cut through red rocks.

A beautiful example of 18th-century engineering still standing tall.

This feature of the city's aqueduct has achieved numismatic fame thanks to its appearance on Mexican banknotes.

In a busy Oaxaca market, a nearly century-old drinks stand still serves family recipes from giant clay pots.

This immense scene of a cosmic battle between a jaguar and serpent illustrates the Aztec concept of the duality of life.