Family (non-mountain) biking in MD or SE PA Campgrounds

[MNPhats]

Hi,

My boys (ages 6 and 8) love to ride their bikes around when camping. Due to their age, I am looking for campgrounds where they could do this safely. This could either be a large campground or a park that has paved trails.

I'm curious if people have any knowledge on campgrounds or state parks like what I have described.

Thanks!

Sean