I brought up this old thread from 2004 because I happened to see a show on PBS last night about Chaco Canyon. This one was narrated by Robert Redford. It got a little hokey and mystical at the end, and it kind of overplayed the significance of a north-south alignment, but that did not detract from most of the show that explained these architectural alignments with the seasonal patterns of the sun and moon.
There were many large structures scattered around this huge canyon, all in various interrelated alignments, but the odd thing was, the huge number of dark, cramped "rooms" appeared to be more structural than inhabitable, and archaeologists were finding indications that the whole area may not have been "inhabited" at all in the normal sense, but only used for huge ceremonies of, apparently, the equinoxes and solstices. As this example
shows, these people were very well aware of the patterns in the sky, and they obviously thought these discoveries were very important
. I'd tend to agree.