Adventure travel is a type of niche tourism, involving exploration or travel with a certain degree of risk (real or perceived), and which may require special skills and physical exertion. In the United States, adventure tourism has grown in recent decades as tourists seek out-of-the-ordinary or "roads less traveled" vacations, but lack of a clear operational definition has hampered measurement of market size and growth. According to the U.S. based Adventure Travel Trade Association, adventure travel may be any tourist activity that includes physical activity, a cultural exchange, and connection with nature.
Adventure tourists may have the motivation to achieve mental states characterized as rush or flow, resulting from stepping outside their comfort zone. This may be from experiencing culture shock or by performing acts requiring significant effort and involve some degree of risk (real or perceived) and/or physical danger (See extreme sports). This may include activities such as mountaineering, trekking, bungee jumping, mountain biking, canoeing, scuba diving, rafting, kayaking, zip-lining, paragliding, hiking, exploring, sandboarding, caving and rock climbing. Some obscure forms of adventure travel include disaster and ghetto tourism. Other rising forms of adventure travel include social and jungle tourism.