Learn more about Upper Manhattan
Upper Manhattan is. a term denoting the more northerly region of the New York City Borough of Manhattan, with its southern boundary defined as anything between 59th Street and 155th Street. Between these two extremes lies the most common definitions of Upper Manhattan as Manhattan above 100th Street, that portion of the borough in which the numbered streets are three-digit numbers (e.g. "West 181st Street"), or above Central Park, north of 110th Street. This definition of Upper Manhattan takes in the neighborhoods of Marble Hill, Inwood, Washington Heights, Harlem, and part of the Upper West Side (Morningside Heights and Manhattan Valley.)
Upper Manhattan could be described as the "non-tourist" section of Manhattan, that part far less influenced by the gentrification that had taken place in New York over the past 30 years, until recently. Not only do New York tourist maps not normally acknowledge the outer boroughs of the Bronx, Brooklyn, Queens, and Staten Island (and if so, only in the most rudimentary way), but they also regularly neglect Upper Manhattan as well. This is likely due to the perceptions that it is less glitzy, less tourist-friendly, and the relatively high-crime nature of the area. Even many native New Yorkers tend to treat Upper Manhattan like an outer borough; its greater distance from Midtown Manhattan and comparatively lower rents lead many to exclude this northern neck from the area New Yorkers call "The City".
Though the Upper West Side is a relatively affluent neighborhood, unlike the other neighborhoods listed above, its northern end has always been regarded as less notable and often outright associated with Harlem, though Morningside Heights and Manhattan Valley actually bear little resemblance to Harlem. Though Manhattan Valley has not quite gentrified, fitting the mold of other Upper Manhattan neighborhoods, Morningside Heights boasts one of the borough's lowest crime rates, as well as the world-renowned Columbia University.
All of Upper Manhattan is contained in the larger area New Yorkers know as Uptown (above 59th Street.) The Bronx, though not in Manhattan, is often colloquially referred to as "Uptown", especially in the context of hip hop/inner-city culture.