Great Valley (Pennsylvania)

The Great Valley, also referred to as the Chester Valley, is a geographic valley located in the southeastern portion of the U.S. state of Pennsylvania. Located within the larger Delaware Valley region, the valley begins at the Schuylkill River in Montgomery County and runs southwesterly through the entirety of Chester County, eventually ending in Lancaster County. While the valley is most distinct through central Chester County, traces of it can be followed almost the entire distance between the Delaware and Susquehanna rivers.

This Great Valley is near and parallel to, but distinct from, the Great Appalachian Valley.