A century ago, a doctor in Poland noticed that workers at a salt mine did not have the same respiratory or lung problems that plagued others. These miners seemed to breathe easier. Today "salt therapy" is making a comeback. A growing natural health trend, it involves breathing in salt-infused air to treat asthma, nasal congestion and other respiratory ailments. Minneapolis is home to the only "salt cave" in the state where salt therapy is offered. Located in a strip mall in the city's Tangletown neighborhood, the Salt Cave is actually a room with zero-gravity chairs and walls and floors covered with 12,000 pounds of rock salt from a mine in Pakistan. Co-owner Scott Wertkin likens the treatment to "a dry Neti pot." 4811 Nicollet Av., Mpls.; 612-567-2587; www.saltcaveminnesota.com