Padre Island National Seashore, Texas
All campgrounds are open year-round on Padre Island, which contains the longest stretch (70 miles, or 113 kilometers) of undeveloped barrier island in the world. Not surprisingly, numerous ecosystems can be found, including a rare coastal prairie, dune system, wind tidal flats and one of the few remaining hypersaline lagoons in the world, the Laguna Madre. Padre Island also sits on the Central Flyway, and so is a critical spot for more than 380 migratory, overwintering and resident bird species -- that's nearly half of all documented species in North America [source: National Park Service].
You can camp on one of five sites on Padre Island: Bird Island Basin, Malaquite Campground, North Beach, South Beach or Yarborough Pass. Bird Island Basin is a prime spot. Sitting on the waters of the Laguna Madre, visitors enjoy fantastic kayaking, boating, birding and fishing. Even better, there's a windsurfing area ranked as the best flat water sailing site in the continental United States by Windsurfing Magazine [source: National Park Service].