Explore the unique natural environment of Fort Mifflin! Walk the top of the walls looking for animal signs, check out the driftwood and shells on the Delaware River beach, check for tracks on the sea wall. Join a guide for a trek to the Mortar Battery, a hidden piece of history nestled unseen in the woods behind the High Battery (must be with guide, 1 pm and 3 pm.) Wear boots and dress for the weather – this is an outdoor excursion! Well behaved dogs on leash are welcome. Social distancing required at all times, masks required for guided group.