There's a great KOA near Ft. Indiantown Gap, PA. It's called Twin Grove KOA, or sometimes is called Pine Grove. We don't normally do a lot of KOA's, but this one is cool. They've got nice sites, a pool with a small water slide and water 'mushroom', a big store/full restaurant, ice cream shoppe, and a small amusement park with an arcade, ferris wheel, carousel, bumper boats, etc. They have a great fireworks show on the 4th of July, with a band and everything. I was told that Halloween was a big thing there with trick-or-treating, etc. They have a small "train" that the kids can get rides in to/from their sites and to the amusement park. You're only about 30-40 min. drive away from Hersheypark, and there is a lot of stuff to see in Harrisburg, like museums, etc. And, you can get to Amish country in about an hour and a half. Just down the road from the campground there is access to a nice bike/jogging path. Our son loves "Roadside Americana" (I think it's called something like that), it's a small place that has a HUGE train layout inside. It's cheap and there are many different types of trains running with some parts that the kids can make work. You're also not far from Strasburg and their steam railroad there, they even have a Thomas the Tank Engine pull the train a couple of times a year. There's a nice real train museum across the street there. There is a Cabela's in Hamburg, PA that is no more than an hour away. We've gone and spent part of the day there looking at the aquariums and all the animals, and shopping. We love going to this KOA, our kids are 11 and 13 and we've made about 4 trips up there. It's all gated going into the campground, so we felt safe in letting the kids go on their bikes with a cell phone to check out the amusement park and ride the rides. We just bought a string of tickets and let them go, and us old folk's got to relax in the shade with a big glass of lemonade and our newspapers/magazines! Good luck, and have fun!
LuAnn