Come to the Greenwood Furnace Folk Gathering on September 11-13, 2015 The Greenwood Furnace Folk Gathering is an event to celebrate the honor of folk music and entertainment. Enjoy folk music workshops, concerts, and dance in the relaxed setting of Greenwood Furnace State Park honoring Pennsylvania music traditions. Friday and Saturday concerts and dance are free and open to the public. The workshops for all ages and musical experience require registration. Special camping arrangements for the event are available through the Park.