Zuni and Hopi Indians sacred places

I am reading a book called "The Way of the Shaman" by Michael Harner. It is very interesting and goes into detail the accounts of the author in his journey to becoming a Shaman. In it it goes into talking about the Zuni and the Hopi Native Americans, and how virtually every home would have a very similar Kiva, which is their ceremonial chambers (church). The means by which you got to the kiva differed on the tribe, but usually a sipapu ( hole) led down into the kivas. These sipapu's are "symbols representing the mythical opening into the Lowerworld" and the Lowerworld is where Shamans go to perform their rituals, they get here by a conditioned altered state of consciousness called the Shamanic State of Consciousness (SSC).
Stephen Brock