I was there two summers ago (August -- not recommended) and greatly
regretted not bringing my camera. You can wander and sit in the old
squares, photograph the pre-Civil War architecture, or trees with
Spanish moss. It's a lovely place. Ask and someone will point out the
square where Forrest Gump was filmed. I took a horse-and-wagon ride,
which gives you an overview of this district.
I didn't take a river ride.
Have fun,
Joe