Northwest Philadelphia - Terrain and Geography

Terrain and Geography

Northwest Philadelphia is known for its hilly terrain, especially in the western half between the Wissahickon and the Schuylkill River. This hilly terrain is a distinct characteristic of Manayunk and Roxborough, making them popular for any recreation that can use a good hill (such as sledding and soapbox derbies, or especially challenging sessions of running and biking). Upper Roxborough, because it is one of the highest elevations in Philadelphia, is the site of a reservoir and many of the city's broadcast transmission towers. Ridge Avenue follows the ridge that divides the Wissahickon valley from the Schuylkill valley.

Learning to navigate successfully across and beyond Northwest Philadelphia requires one to keep in mind that Northwest Philadelphia's street grid is oriented along axes of northeast-southwest and northwest-southeast (X). These axes are skewed almost exactly 45° from the true north-south and east-west axes of Philadelphia's main street grid (+). Within any one neighborhood, it is easy to mentally discount the east-west gradient and think solely in terms of north-south, uphill-downhill, or (perhaps worst) to conflate those two, with the mental axis of "up"-"down" concealing the conflation. Any time that one begins to extrapolate too far along these lines, one is losing orientation with surrounding areas.

Northwest Philadelphia is an area where exceptions to the regular pattern of the street grid are plentiful. The Wissahickon gorge rather thoroughly divides the "halves" of Northwest Philadelphia because of the relative scarcity of road crossings. The rail lines tend to rather thoroughly divide adjacent neighborhoods, for the same reason. One-way streets are not uncommon, and neither is the event of a bend interspersed within the rectangular street grid. Manayunk's street grid evolved completely independently from Germantown's, which makes perfect sense from a historical perspective. The result of all these factors is that navigating in Northwest Philadelphia can be a very different experience depending on whether one is traveling by motor vehicle or on foot or bicycle. Navigating solely by motor vehicle can leave one with a rather distorted sense of how far away certain points are from each other. When one explores on foot or bike, one restores a more accurate sense of orientation.