The John Heinz NWR at Tinicum, America's First Urban Refuge is located in Philadelphia and Delaware Counties, Pennsylvania about 1 mile from Philadelphia International Airport. The refuge was established by an act of Congress in 1972 to protect the largest remaining freshwater tidal marsh in Pennsylvania; approximately 200 acres. When acquisition is complete, it will consist of 1000 acres of varied habitats.

The Refuge trails are open daily from sunrise to sundown. The Visitor Center is open daily from 8:30 am to 4:00 pm.