This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

A cabinet of curious mathematical models and old calculators.

A natural history wunderkammer in the middle of the desert.

This reclusive Hopi village in Arizona has been continuously populated longer than anywhere else in America.

A working cattle ranch with remarkably well-preserved prehistoric petroglyphs and ancient ruins.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

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

A mysterious spirit totem at the edge of Navajo lands.

A mysterious "wedding cake" castle in the middle of the urban desert.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

This southwestern historic site was designed and built by an artist who wanted his work to "feel at home."

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

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

Ancient pueblos built into the base of a natural canyon wall.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Limestone caves with spectacular showcase chambers.

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

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

The Magical World of George Phar Legler.

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

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

See massive fossils that are over 200 million years old in northeastern Arizona.