“…One of the most serious threats is posed by the demand for "nature sports" (including skiing, skin scuba-diving, rock climbing, rafting, yachting, surfing, golf, paragliding, and other sports performed in an undeveloped natural environment), which is likely to increase in the future [12][13][14]. This is because urban areas are becoming increasingly polluted, and people thus increasingly want to return to nature; this desire is supported by economic affluence and leisure time [15,16]. In South Korea, the number of hikers and holidaymakers in mountainous and marine areas is increasing rapidly every year; leisure activities such as yachting, wake surfing, water skiing, golf, skiing, and camping are gaining popularity, as are new sports activities such as rock climbing, orienteering, mountain biking, and windsurfing [4].…”