One of the more expansive CCC-built state parks, Poinsett State Park (6660 Poinsett Park Rd., 803/494-8177, www.southcarolinaparks.com [1], daily 9 a.m.–9 p.m., free) is known for its particular appeal to hikers. The extensive system of in-park foot, bike, and horse trails link up with the Palmetto Trail (www.palmettoconservation.org [2]), which goes on into the adjacent Manchester State Forest.
Because of its key location where the Midlands [3] sandhills meet the Coastal Plain, the topography is unusually interesting for this usually-flat area. Wildflower displays in May are particularly nice. The 10-acre lake has a coquina bathhouse from the 1930s, and you can rent a boat to do some angling yourself.
There are 24 campsites with water and electricity ($12), and 26 designated tent sites with just water ($9). For a decidedly more plush stay, there are five fully furnished cabins ($45–100) complete with fireplaces.
Links:
[1] http://www.southcarolinaparks.com
[2] http://www.palmettoconservation.org
[3] http://www.moon.com/destinations/south-carolina/columbia-and-the-midlands