The 64,500 sq. ft., two-story Miller Activity Complex (MAC) referred by the town as the “crowning jewel” of Philip S. Miller Park, features a natatorium complete with leisure amenities and fitness lap lanes, a 23-foot-tall indoor playground, a 3,500 sq. ft. indoor flex play area, indoor turf field batting cages, a golf simulator, locker rooms, and administrative offices for the Town of Castle Rock Parks and Recreation staff.