The beach is the main attraction on South Padre, and there are some 25 miles of white-sand to choose from. Condos and hotels line much of the beachfront, but there are more than 20 beach access points with free parking. However, if it's pristine, deserted stretches of sand you're looking for, you're on the wrong island. Instead, plan a trip to Padre Island National Seashore: with a 4WD you can explore miles of Gulf Coast white sand to your heart's content (at a 15 mph speed limit). The best shell collecting? Aptly named Big Shell Beach, about halfway down the island.