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

This 1930s log cabin began as a taxidermy museum but is now a popular country music venue.

Named for the 39 tribes that live in Oklahoma, this restaurant's menu deliciously highlights local flavors.

Founded by members of the Tohono O’odham Nation, this one-room joint's James Beard–winning fry bread is light as a cloud.

Dramatic river bend surrounds a natural red-rocked pedestal.

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

Rippling sand dunes frozen in the Arizona rock.

This Native American settlement dates back to the Pueblo II period.

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

An incredible airplane graveyard sits outside this small museum dedicated to preserving aviation history.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

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

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

A mass grave for victims of an airline disaster that led to much-needed safety improvements for commercial flights.

Crafted in 1911, this steam locomotive spent its entire working life in Flagstaff.

The wreckage of a deadly bomber plane crash can still be found near an Arizona peak.

Bootleggers ran booze beneath this building before (and after) Route 66 appeared beside it.

A mysterious spirit totem at the edge of Navajo lands.

This historic national park is covered in the stunning ruins of red rock pueblos.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.

The remains of this hell for leather wild west town can still be found in the Arizona desert.

A stealthy Apache hideaway that became the haunting site of a mass grave.

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

Although now a decaying ruin, this stone cabin's history includes several notable figures.