THE PHILADELPHIA COUNTY LAND BRIEF
Land in the
Piedmont Uplands setting.
Philadelphia County has 134.3 square miles of land in Pennsylvania. 2 mapped landscape regions meet across Philadelphia County: Piedmont Uplands, Delaware River Terraces and Uplands.
Rounded low hills, open valleys and irregular plains form a transition between Appalachian highlands and the coastal plain. The underlying geology mixes metamorphic, igneous and sedimentary rocks.
Regional context: Northern Piedmont ↗ · Regional mapping across the county footprint
Where the landscape changes
Philadelphia County intersects 2 mapped regional units. The largest mapped shares are:
- Piedmont Uplands56.4%
- Delaware River Terraces and Uplands43.6%
Middle Atlantic Coastal Plain in Philadelphia County
Low coastal plains contain terraces, estuaries, marshes and barrier islands. Unconsolidated sediments underlie this varied coastal setting, with forest patterns changing near streams and low-lying areas.
Read the regional source ↗Finding your parcel within Philadelphia County
The atlas lists 1 cities, towns, townships, and Census communities associated with Philadelphia County, including Philadelphia. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Philadelphia County by land and water
The Census records 8.1 square miles of water within Philadelphia County, or 5.7% of its total area. That share is close to Philadelphia County’s 5.7%. This is geographic context; waterfront status and usable land must be checked at the parcel.
The Census boundary meets Bucks County, Delaware County, Montgomery County within Pennsylvania. A tract near one of these lines should be matched to the county identifier on its own records.

