Wildwood was my favorite as a kid. I remember it got shut down years ago. I think it was near bankruptcy. Today I looked it up to see what happened to it. It looks like time has made it a quiet neighborhood. Another good one was Dover Lake.
They closed in 2006 for undisclosed reasons.
Brandywine ski resort purchased it and it looks like everything is still there, at least according to this overhead photo from bing, whenever that was taken.