Sometimes the outline of the ancient town was square or almost square, the house-blocks were of the same shape, and the plan of the town was indistinguishable from a chess-board.

Or, instead of squares, oblong house-blocks formed a pattern not strictly that of a chess-board but geometrical and rectangular.

Often the outline of the town was irregular and merely convenient, but the streets still kept, so far as they could, to a rectangular plan.

Sometimes, lastly, the rectangular planning was limited to a few broad thoroughfares, while the smaller side-streets, were utterly irregular.

Other variations may be seen in the prominence granted or refused to public and especially to sacred buildings.