Paddlers in particular will enjoy Goodale State Park (650 Park Rd., 803/432-2772, www.southcarolinaparks.com [1], Fri.–Sun. 9 a.m.–6 p.m., free) a little ways northeast of Camden [2]. The only drawback here is the curtailed days of operation. A Civil War–era mill pond combines with a nice cypress ecosystem.
There’s a marked, three-mile canoe/kayak trail through the cypress swamp, which includes a pass by a great heron rookery. Rent a canoe for $12 a day.
Links:
[1] http://www.southcarolinaparks.com
[2] http://www.moon.com/destinations/south-carolina/columbia-and-the-midlands/outside-columbia/camden