Folly Beach, Charleston
Folly beach is about ten miles south of historic Charleston. It's a good getaway if you want to supplement your historic sightseeing with some beach culture. The beach is accompanied by a town that has restaurants, bars and souvenir shops. Some parts of the beach, mainly around the pier, are packed with people, but if you walk a little bit farther the crowd thins out significantly.
Folly Beach is about twenty minutes away from Charleston, past Johns Island and James Island. There is a public pier as soon as you come to the island, which is great for fishing and pictures. There is also Folly Beach County Park, which is a nice place to go if you don't want hotels or houses in your way when you visit the beach. This beach is my favorite.