Nude recreation refers to recreational activities which some people engage in while nude. Historically, the ancient Olympic Games were nude events. There remain some societies in Africa, Oceania, and South America that continue to engage in everyday public activities—including sports—without clothes, while in most of the world nude activities take place in either private spaces or separate clothing optional areas in public spaces. Occasional events, such as nude bike rides, may occur in public areas where nudity is not otherwise allowed. While nude recreational activities may include sports such as tennis or volleyball, nude sporting activities are usually recreational rather than competitive or organized. Recreation and Leisure Recreation is any human activity done for pleasure (or "play") during leisure time as opposed to those activities that are necessary for survival. Historically, this means that recreation only existed after human society reached the stage where leisure time existed, perhaps during the late stone age (Upper Paleolithic), as shown by the first appearance of cave paintings and musical instruments. Modern concepts of recreation begin with ancient civilizations. Sport is any activity recognized as requiring physical skill. Any sport may be recreational for the participants, while viewing sports is a recreation for spectators. Naturism Naturism, or nudism, is a cultural movement practicing, advocating, and defending personal and social nudity, most but not all of which takes place on private property. The term also refers to a lifestyle based on personal, family, or social nudity. Research indicates that contrary to public opinion, naturists are otherwise typical members of society who engage in social activities such as volleyball, swimming, and tennis in the same manner as at other resorts, just without the clothing. In keeping with their basic function, naturist clubs and resorts feature recreational activities. Naturist recreation also includes cruise ships, which offer a variety of activities.