Located on the island between Northumberland and Sunbury and the adjacent mountain, the Shikellamy State Park Marina and Lookout are hidden gems in Central Pennsylvania.
The marina has boat docks and launches on both branches of the Susquehanna River and offers a fairly flat one mile walking/biking trail. Also in the park are many picnic tables and a beautiful butterfly garden maintained by a local hortocultural club. More info is available at the Friends of Shillelamy Park website.
The lookout offers breath-taking views of the two towns, river branches and island.