Anasazi Cliff Dwellings
Mesa Verde is still a mystery even today. The Cliff Palace contains about 150 rooms. There are workers down there who take good care of the palace, like fixing walls or stairs and trimming trees and bushes. Why the Anasazi built their dwellings into the walls of the canyon, and why they suddenly left without a trace, no one has figured that out yet. And unless we find papers or drawings, we might never know.