Limestone caves with spectacular showcase chambers.

This quirky hot springs town known to locals as "T or C" was named after a radio show.

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

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

This giant steer-skull edifice refuses to die.

This water tower slanted at an uncomfortable angle off the old Route 66 was an ingenious marketing ploy.

The world's second largest rocking chair is found on Route 66 in Cuba... Missouri.

The world's largest fully steerable radio telescope.

Take a steam-powered ride straight out of the past on this Appalachian rail line.

Entombed in this strange, white stone hill are the deadly remains of radioactive weapons production.

Giant works of art interspersed throughout meadows and woodlands offer a new discovery at every turn.

This private residence was the template for one of the most beloved television homes of all time.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Honoring the famed folktale author, this California museum looks like it belongs in the Black Forest.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

San Francisco's newly reopened hands-on science museum.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

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

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

The stone circle honors the 19 firemen who perished during the Yarnell Hill Fire.

A $100,000 tumbleweed decorates an Arizona park and ride that got its priorities a bit tangled.

Every year, festive decorations appear on this juniper tree located in the median strip of a busy highway.

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