 In the early 1960s, ""Monopoly" happenings" began to occur, mostly marathon game sessions, which were recognized by a "Monopoly" Marathon Records Documentation Committee in New York City.In addition to marathon sessions, games were played on large indoor and outdoor boards, within backyard pits, on the ceiling in a University of Michigan dormitory room, and underwater.In 1965, a 30th anniversary set was produced in a special plastic case.