Charleston architecture is wonderful, well worth the trip all by itself. Also some very interesting Civil War era ruins and restorations more out in the surrounding areas.
One of my early professional assignments was shooting Charlseton architecture. What made it really hard was that while temperatures were hovering over 90F, humidity was limiting visibility to maybe 40 feet. Which made for some nice misty shots of the ruins. But I thought I was going to die. I was literally worried about getting too far from the air conditioned car, which is all that saved me! Of course I was disadvantaged by a lifetime of acclimatization to 20% humidity. But you gotta think about those things, climate can hammer you sometimes.