Geothermal hot springs come to the surface in a steep-walled valley at the end of the road, beyond the state recreation area. An ingenious Fairbanks entrepreneur’s resort stands here, with a museum made entirely of ice; greenhouses heated with geothermal water, producing food for the restaurant; and an innovative electrical system powered by the springs. Best of all, a series of steaming pools are open for swimming, including a rock-rimmed outdoor pool where you can float in hot water under cold skies.  To stay overnight, choose either the best rooms, which are quite good, or the yurts; the midrange rooms ain't great, and service can be inconsistent. The restaurant and bar are quirky and fun. The resort offers many activities, as well.