Authentic Nordic sauna, cold plunge, steam room, and thermal soaking tubs in the heart of Union Station Denver — Colorado's most complete contrast therapy experience. Step into ROK SPAS, home to the largest sauna in Denver. Our traditional sauna seats 40 guests at 194°F, paired with five different cold plunges set at accessible temperatures from 37°F to 55°F, an aromatic steam room, and warm thermal soaking tubs — everything you need for a full Nordic bathing circuit in downtown Denver.