Outdoor adventure or outdoor sport refers to recreational activity engaged outside, usually in outdoor natural settings. The activities which encompass outdoor sports vary according to the physical environment they are being performed in. These activities include but are not limited to hiking, mountain climbing, backpacking, fishing, kayaking and snorkeling, mountaineering, mountain biking, surfing, rafting, fishing, hiking, and many more. Many people engage in outdoor activities as a hobby, and some go outdoors just for fun. Outdoors can do activities during leisure time, work time, or on vacation.