Like many Alaskan parks, getting to Kobuk Valley, in northwestern Alaska, is tough (and expensive), since you have to hail an air taxi in Nome or Kotzebue. And don't expect much in the way of amenities once you get here: Trails and roads simply don't exist within the park's 1.7 million acres. Still, hardy outdoors types are drawn by hiking, biking, dog mushing, fishing, boating, and wildlife viewing. Don't squeeze in too much, though: The scenery is gorgeous, since you're surrounded by two mountain ranges that give protection to the central part of the Kobuk River. Go play among the many dunes, a result of glaciers grinding and carrying tons of sand to this valley.