While Yonge "officially" divides Toronto east and west, is the Don more appropriate in terms of a boundary? Is crossing the Don liking crossing the Thames in London (in London there's the urban legend of cabs not wanting to go south of the Thames, it's less served by the tube etc.) The east and south sides of the river in both cities developed later. About 40% of London's population is south of the Thames. I don't know what percentage of Torontonians live east of the Don offhand. The analogy may hold better though if Old Town/St. Lawrence had remained the "city center."