Sioux Campground

This campground is labelled "rustic" camping by PA State Parks, meaning it provides a fire ring and picnic table at each campsite, and 3 port-o-potties for all sites to share. (Under the Amenities list of this page it mentions the Sioux sites have showers and RV hookups/sanitation - they don't). This my hands-down absolute favorite place to go for a quick overnight trip, and there is always at least one site open even if I book last minute. The only potential downside is that it's only a few miles from the Pittsburgh International Airport, and so you'll definitely hear (and maybe even see!) some jets flying overhead throughout your stay.