Deep in the Rockies is one of nature’s best gifts for spa lovers: the healing thermal waters at Glenwood Hot Springs. These 93° natural pools are the world’s largest and come with Rocky Mountain views. $15; hotspringspool.com
Best time to go: For fewer crowds, November.
Stay: Teddy Roosevelt and Al Capone stayed at the 1890s Hotel Colorado back in the day. From $99; hotelcolorado.com