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

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

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

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

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

A spiritual vortex among the red rocks in Sedona.

An urban laboratory.

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

This sinkhole in the Arizona desert is filled with carbonated, arsenic-rich water