WUPATKI NATIONAL MONUMENT — Absorbed as they are by the magnificence of the scenery surrounding them, most people who visit these ancient ruins walk right past “the blow hole” because it looks more like a square sandstone bench than part of an archeological dig. Located near the ceremonial ball court east of the major ruins, the blow hole is a crevice in the earth’s crust that creates the impression that it’s capable of breathing. It connects to an earth crack, an underground passage formed by earthquake activity in the Kaibab limestone bedrock.

The hole reacts to barometric pressure above ground. When the air is warm and light above, the cold air from below blows out with such force that it can make your hair stand straight up. But when the air gets heavy and moist, it reverses itself and sucks the air down.

To date, no one has figured out what, if any, use the blow hole served for the ancient ones who built the Wupatki complex. Today, the Hopi descendants of the original builders call it “Yaaponsta” (the Wind Spirit). The Wupatki ruins are about 30 miles northeast of Flagstaff off Highway 89.