I can't get enough of Caw Caw Interpretive Center County Park. If you go there in the spring and summer, you'll probably see alligators, a bald eagle, cool bugs, and other exciting wildlife. If you go there in the winter, well ... at least there's no mosquitos!
Caw Caw is still relatively unknown in this area, so the park is never crowded--and besides, it's huge. They have a bunch of different "habitats" like rice fields, marshlands, upland forest, etc.
Caw Caw also offers fun classes, like organic gardening or pine needle basket-weaving.
In short, Caw Caw is a beautiful park and worth the drive out of Charleston.