Explore the state of Delaware
Port Penn is part of Fort Delaware/Fort Du Pont State Park and includes the Port Penn Interpretive Center that is open weekends/holidays from Memorial Day to labor Day. Park at the Interpretive Center and walk across Rt 9 to the Port Penn Wetlands trail. The trail could have a sign "Trail open Sundays only Oct 1 to Feb 28", but this is for the section of trail over the causeway that is Fish & Wildlife Land. You will only go a short ways and not leave state park property so it is okay to use the trail that will take you to old muskrat skinning shack and floating fishing shed. When the trail is open, it is a nice but long walk through the marshes and out to Delaware River.
DGT Port Penn (Coordinates) - N 39° 31.117 W 075° 34.688