A hollow cement depiction of time's inexorable effect on the human body.

Faces carved into the cliffs create an otherworldly walking trail.

Stroll through a wonderland of stupendous moss-covered trees.

Steep canyon walls hide a forested oasis in the West Texas desert.

A 6-mile-long lake created by an apocalyptic seismic event and the deadly chain reaction that ensued.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.