Without boring you with tons of pics, let me try to show what is so extraordinary about the architecture of Chaco---remember this is built by a people using only hand held tools--sharp corners to the walls, doors, windows and where 2 walls intersect/meet--no curves, unless an intended round shape was intended, as in the Kiva's. In addition, the walls were faced with another stone layer, even more precisely tooled than the inside wall--like a finishing surface in today's homes. They also built with strength in mind of the weight of a 3 story dwelling--tapering the base--again as in current construction design, where reinforcing 'rebar' is not available or desired by the builder. But remember this is 990-1250AD not 2006!!