Don't know if you've gone yet, but yeah, the Rancocas Nature Center is a really cool place. I used to got there all the time with my grandmother when I was a kid, saw quite a few bluegrass festivals there before they stopped having them, and have hiked the trails out back more than a few times, I especially like the pine grove in the middle of everything. The center itself is an 130 year old farmhouse, very intersting little exhibits, a few animals, and a store inside. If it's still there, they used to have a little research library in there too.
Brian