This turn-of-the-20th-century ranch, run by the Arizona chapter of the Nature Conservancy, has five comfortable casitas with kitchens and modern plumbing, set in the pristine grassland foothills of the Galiuro Mountains. Four are built around a courtyard hacienda-style. The fifth, a stone cabin set off by itself for more privacy, is the only unit open to families with children. The ranch has a visitor center, 22 miles of hiking trails, and private natural hot springs. There's a two-night minimum stay.