Eric, there's one in Pa, out near Lancaster. Not sure if it is big, small or what. Given that it is in Pa and there isn't a real castle within 3000 miles of the spot, I guess it can't be that big. But here's a link anyway.
Pennsylvania Renaissance Faire
I do know it is close to Stoudts Brewery. So after smoting the barbarian hordes, you can stop by for a couple of brews.