Dividing the whole into parts: are NY and LA unique?

How unique are our two largest cities in the way they subdivide space within their city limits (both offically and informally)? All cities have differential parts. Virtually every city has neighborhoods vastly differet from each other with little in common. But do any cities have the all-encompassing, massive divison of space that you can see in New York and Los Angeles? I'm talking about: New York : The geography divides the city into two islands (Manhattan and Staten Island), a section on a very large island (Brooklyn and Queens on Long Island) and a section on the mainland (Bronx). Manhattan at one time was New York and to many remains "the city". Brooklyn and Queens are separated from it by the wide East River. Staten Island is literally its own world. Only the Bronx seems to share a physical closeness to Manhattan across the Harlem River. And no borough's development seems so Manhattan-related as the forever uptown moving city had to cross into the Bronx for continued growth. Meanwhile, Brooklyn's former status as a large independent city gives it a flavor all its own.Any way you slice it, the outer boroughs (however urbanized they are; and they are) give the impression of a transition zone between the heart of the city (Manhattan) and outlying areas in New Jersey, Long Island and Westchester...something not seen in other cities. Los Angeles: offically there are no internal divisons between city, valley, and harbor. Unoffically they are world apart. The Santa Monica mountains form far more of a divison between the LA Basin and the majority of the San Fernando Valley that is the city of Los Angeles than the East River or NY Bay could ever do in NYC. Mulholland Drive looks out on two different worlds. To get to San Pedro down on the harbor, LA had to exend a small strip of land to take it a place that feels like and is located nearer to Long Beach than it is to the heart of LA. The LA model of "zones apart" is even further supported by the numerous cities it surround: Beverly Hills, W Hollwyood, San Fernando, Universal City, etc. And in the case of Beverly Hills, you have an independent city that feels more part of the heart of the city than areas out in the valley that actually are in LA. Is there anything comparable to what NY and LA do to divide space? I would think no: I see nothing in Chicago's clearly defined north, south, and west sides, in DC's NE, NW, SE, SW, or even in Boston's areas north of the Charles River and west of Fenway that would suggest anything near to the NYC and LA models. Thoughts?>