anchor: Whereas the nucleus of Florence was built to a strict Roman city plan of straight streets intersecting at right angles, Siena has all the Tuscan hill-town's haphazard organic forms, straggling up and down a forked ridge of not one but three hilltops.
positive: The center of Florence was built using Roman city plans while Siena has roads going in all directions along the hills.
negative: Siena was destroyed and rebuilt to adhere to Roman city planning.