One of the first aspects of Middle American culture which strikes an amateur as interesting and possibly significant is the ordered arrangement of the buildings in almost all sites. Like those of Egypt—and unlike those of Greece and Rome —the sites seem to have been planned on a large pattern. The individual buildings are arranged according to a scheme which gives them space and which orients them on a common axis. They are not dropped in helter-skelter, crowded cheek-by-jowl, and set at odd angles to one another. Further, the city plans of Middle America seemollow fhe another and larger pattern. This is the pattern of the north and south axis of each site and each building. This orientation almost invariably follows one of three schemes. I t is sometimes true north, sometimes about 7 degrees east of north, sometimes about 17 degrees east of north, but practically never west of north. There are some sites which have no general pattern, and therefore no orientation.