Seawater Spa at Gurney’s
This resort on a prime stretch of Montauk coast underwent a total renovation in 2014, which included a reimagining of the spa and the restoration of the Olympic-sized saltwater swimming pool, which uses sand-filtered water drawn from the sea. A Finnish-style sauna was also added, where guests can pour aromatherapy-enhanced water over hot stones, and there’s also a eucalyptus oil-infused steam room. Set at 120 degrees and 100 percent humidity, a few minutes here is meant to help the body release impurities through sweating. As one of the only places open year-round, it’s an ideal off-season getaway, too.