5. Prospecting for Dollars at Cumberland Island National Seashore, Georgia

No, not the US Treasury minted variety - we're talking sand dollars here! The practically deserted 17-mile stretch along the island's Atlantic coast offers shell hunters unrivalled access to specimens that are still pristine and haven't been picked over by some tourist or beady-eyed gull. The National Park Service strictly controls access by ferry and there's no bridge across, so you can beachcomb for hours without being disturbed by rival shell hunters. Cumberland Island is not just one of the best shelling beaches in the US. It's a wonderful place to come and observe wildlife. Go to the marshland on the western side of the island - with a bit of luck you may find shark teeth. Cumberland Island is home and nesting ground to the highly endangered loggerhead sea turtle, so please mind your manners and respect their marked nests.