The exact use of of these structures is not known. Some theories are that the Ancestral Puebloans used them conduct healing ceremonies or to pray for rain, luck in hunting, or good crops. They are usually partially or totally subterranean.
This is the next image for display in the Art in Healing gallery from April 1- June 28, 2013. It will be available as a 16x24" gallery wrap on Metallic Paper.