We've camped on the beach at Padre Island National Seashore twice. The campground has always been fully booked but there is access to the beach and you can camp on the sand. It gets a little crowded on holiday weekends but there are MILES of sand so you can just drive until you find a spot that suits your fancy. I have a 2WD vehicle and was a little concerned about getting stuck. Fortunately, there were plenty of people on their beach with 4WD who were more than willing to use their toy to pull me out.

I contemplated giving my review fewer stars because this is Texas and the beaches are not nearly as nice as those in other parts of the US. We had issues with seaweed washing up both times but the water was clean. There are no facilities on the beach but the visitors center has showers and flush toilets.