Editing Delaware County, Pennsylvania (section)

==Geography==
[[File:Bartrams Bridge NRHP.JPG|thumb|[[Bartram's Covered Bridge]], built 1860 west of [[Newtown Township, Delaware County, Pennsylvania|Newtown Square]], crosses [[Crum Creek]] into [[Chester County, Pennsylvania|Chester County]]]]
[[File:NewlinMill.JPG|thumb|[[Newlin Mill Complex|Newlin Mill]], built 1704, on the west branch of Chester Creek, near [[Concordville, Pennsylvania|Concordville]]]]
According to the [[United States Census Bureau|U.S. Census Bureau]], the county has a total area of {{convert|191|sqmi}}, of which {{convert|184|sqmi}} is land and {{convert|6.8|sqmi}} (3.5%) is water.<ref name="GR1">{{cite web|url=http://www2.census.gov/geo/docs/maps-data/data/gazetteer/counties_list_42.txt|website=United States Census Bureau|access-date=March 6, 2015|date=August 22, 2012|title=2010 Census Gazetteer Files}}</ref> It is the third-smallest county in Pennsylvania by area.

Delaware County is roughly diamond- or kite-shaped, with the four sides formed by the [[Chester County, Pennsylvania|Chester County]] boundary to the northwest, the boundary with the state of [[Delaware]], a portion of the "[[Twelve-Mile Circle]]") to the southwest, the [[Delaware River]], forming the border with the state of [[New Jersey]]) to the southeast, and the city of [[Philadelphia]] and [[Montgomery County, Pennsylvania|Montgomery County]] to the east and northeast.

The [[List of U.S. states by elevation|lowest point]] in the state of Pennsylvania is located on the Delaware River in [[Marcus Hook, Pennsylvania|Marcus Hook]] in Delaware County, where it flows out of Pennsylvania and into [[Delaware]]. The highest point in Delaware County is 500 feet at two points southeast of Wyola in Newtown Township.<ref>{{Cite web|url=http://www.dcnr.state.pa.us/topogeo/pub/ic4.pdf|title=Elevations in Pennsylvania|archive-url=https://web.archive.org/web/20011116132201/http://www.dcnr.state.pa.us/topogeo/pub/ic4.pdf |archive-date=November 16, 2001 }}</ref>

Waterways in Delaware County generally flow in a southward direction and ultimately drain into the Delaware River. The waterways are, from west to east: the [[Brandywine Creek (Christina River)|Brandywine River]] (forming a portion of the county's western boundary with Chester County), [[Naaman's Creek]], Stoney Creek, [[Chester Creek]], [[Ridley Creek]], [[Crum Creek]], Muckinipates Creek, [[Darby Creek (Pennsylvania)|Darby Creek]] and [[Cobbs Creek]] (forming a portion of the county's eastern boundary with Philadelphia). Crum Creek was dammed in 1931 near [[Pennsylvania Route 252]] to fill [[Springton Lake]] (also known as Geist Reservoir), an approximately {{convert|391|acre|km2|adj=on}}<ref>{{cite web|url=http://crcwatersheds.org/crum|title=Crum|website=Chester – Ridley – Crum Watersheds Association<!-- Bot generated title -->|archive-url=https://web.archive.org/web/20081016023857/http://crcwatersheds.org/crum|archive-date=October 16, 2008}}</ref> drinking water reservoir maintained by [[Aqua America]], the county's largest lake.

The [[Trainer Refinery]] and the [[Port of Chester]] are located along the shores of the Delaware River.

With its location in the southeastern part of the state, Delaware County is the only county to border both Delaware and New Jersey.

===Adjacent counties===
*[[Montgomery County, Pennsylvania|Montgomery County]] (north)
*[[Philadelphia County, Pennsylvania|Philadelphia County]] (northeast)
*[[Gloucester County, New Jersey]] (southeast)
*[[New Castle County, Delaware]] (southwest)
*[[Chester County, Pennsylvania|Chester County]] (west)

Delaware County is one of four counties in the United States to border a state with which it shares the same name (the other three are [[Nevada County, California]], [[Texas County, Oklahoma]], and [[Ohio County, West Virginia]]).

===National protected areas===
[[File:TinicumNWR.jpg|thumb|[[John Heinz National Wildlife Refuge]]]]
*[[First State National Historical Park]] (part)
*[[John Heinz National Wildlife Refuge]] (part)

===State protected area===
{{convert|2600|acre|km2|0}} of the county are occupied by the [[Ridley Creek State Park]].