Geothermal bathing is just as crucial an Iceland itinerary item as ice cave touring and glacier hiking (and horseback riding, and whale-watching, and road-tripping to geysers, volcanoes, waterfalls, mountains, and fjords…). In fact, soaking in warm water -- whether in one of Iceland’s many natural hot springs, a geothermally heated hot tub under the stars, or in a spa whirlpool -- is the perfect antidote to an adventure-packed day exploring an icy-cold, otherworldly terrain. Read on for the Iceland hotels with the best spa facilities, from Reykjavik boutique hotels to remote escapes in Iceland’s dreamy countryside.