One could make the case that the history of Chestnut Hill is founded on that coming together of these two roads -- Germantown Avenue and Bethlehem Pike -- originally two Native American trails.
For three centuries these two routes have served Chestnut Hill. Even in the late twentieth century, they provide the only direct road-ways through the center of the community. During the early decades, these roads allowed Chestnut Hill function as a what might be called a "gateway village." Like Charlestown and Cambridge outside Boston, and similar fringe communities near Baltimore and New York, Chestnut Hill sat astride a main road (in this case, two of them) that ran into the city and allowed the village to serve as a commercial gateway to the metropolis beyond.Although incorporated by Philadelphia in 1854, Chestnut Hill has maintained its village like character. This is in part because of its proximity to the Wissahickon Valley, which forms its western boundary and isolates it from the rest of the city.
-- David R. Contosta, Suburb in the City, 1992.