Mason is... the largest city in Warren County, which is near the southwest corner of Ohio. Warren County is “Ohio’s Largest Playground” and Mason is the anchor. Come to Mason and stay for the fun! Regional attractions include the Golf Center at Kings Island, Great Wolf Lodge and Conference Center, Kings Island amusement park, and the annual Western & Southern Open. Local attractions include the Mason Community Center and Mason Historical Society’s Alverta Green Museum. Residents and visitors look forward to the annual Mason Heritage Festival, Christmas in Mason, and a wide variety of classes and events for all ages at Mason Community Center.