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

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

A burnt-out motel with priceless Native American artwork in the basement, redeveloped into apartments.

This psychedelic tromp l'oeil seems to be beckoning drivers to crash into a wall.

"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.

Paths are maintained, but trees have taken over plots.

This pseudo-steampunk weapons facility is the world's largest wood and glue structure, and packs quite a wallop.