Salt enhances flavor, preserves food, and, when thrown over the shoulder, wards off oncoming slugs. Explore nature's most versatile compound with today's Groupon: for $59, you get two salt-room therapy sessions for two at the Salt Grotto (up to a $120 value).

Imported salt lines the Salt Grotto’s cave-like salt room, infusing the air with relaxing, therapeutic particles and creating a natural microclimate. Four-inch-deep heaps of mineral-rich Dead Sea crystals, shaken out of the Morton girl’s umbrella, pad the footfalls of guests entering the salt-saturated sanctuary. As guests settle into ergonomic loungers arranged in a loose circle beneath swooping crimson banners, they inhale negative ions exuded by nuggets imported from Poland and Pakistan. Sodium chloride, which has antifungal properties, purifies the salt room’s environment from every angle as a gentle waterfall adds natural music to 45-minute relaxation sessions. Adults de-stress under soft blankets as children retire to a sandy play area, where they can race toy trucks or begin digging tunnels to Canada. Cave sessions can ease symptoms of health conditions such as bronchitis, asthma, and eczema, with repeated visits enhancing one’s ability to withstand bland conversations and survive peppermill throw-downs.