A clear blue swimming hole with hidden caves, still unexplored.

In 1975, a forestry worker in Arizona claimed to have been abducted by a UFO.

The first permanent memorial to a unique secret weapon of World War II.

In this small Phoenix taxidermy emporium, you can find everything from a squid in a jar to a freeze-dried toad.

A historic hydroelectric power plant serves as the unusual backdrop for a public park.

A geological mystery on Camelback Mountain.

A towering bronze statue memorializes the founding father of postwar American conservatism.

This rustic cabin, outfitted with gun slits, was once home to John D. Tewksbury, patriarch of the bloodiest family feud in American history.

Once a year, at exactly 11:11 a.m., this monument comes to life.

This tucked-away cemetery is the final resting place of a prospector who uncovered one of the largest gold mines in Arizona.

Opinions differ as to whether this Arizona tree was actually used as a Wild West jail, but that hasn't stopped the town from capitalizing on it.

One of the best-preserved ghost towns in Arizona speaks to the difficulties of establishing mining towns in the 19th century American West.

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

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

More than 25 fully functional scale replicas of famous lighthouses dot the shores of Lake Havasu.

This once-booming Gold Rush town is now home to a herd of feral donkeys.

A secret fresh water spring for animals and humans alike hidden along the most famous road in the United States.

All of the 20 occupied houses in this mostly abandoned town feature some curious display of junk art.

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

Thousands of glyphs created by an unknown culture decorate the rock formations of this canyon.

A series of labyrinths in the Nevada desert inspire meditation and calmness.

This former open-pit manganese mine is now a massive graffiti canvas.

These markers are used to document elevation changes around the famed dam.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.