i also thought penwell was part of warren cty and i have lived here along time! There isn't a whole to visit in penwell but there is a nice park and hunting and fishing and trails to hike, there is a museum on Mustconetcong Valley Road #97 not far from Penwell, it's the old school house and it's kind of interesting and the woman who is there is really really very nice, enjoy if you get to visit. sincerely, teresa.