They are also used for abseiling (rappelling) and as fixed ropes climbed with ascenders. Ecotourism activities include spelunking, rappelling and hiking. These may involve camping, backpacking, hiking, canoeing, rafting, climbing, caving, rappelling, and other activities. Extreme sports include mountain biking, rappelling, spelunking and more. It organises activities such as parasailing, rock climbing, rappelling, trekking and camping, paragliding. Vertical caving requires the intimate understanding of ropes, knots, anchors, rappelling devices and ascending systems. Young Marines learn survival techniques, physical training, hiking, swimming, rock climbing, rappelling, scuba diving, etc. This is an ecotourism route with activities such as canopy climbing, rafting and rappelling. Climb on Safely training and CPR certification are required for climbing and rappelling events. The trail itself winds through forests, bogs, slippery moss-covered ladders, climbing, rappelling and beach treks. There are many knots used in climbing, rappelling and mountaineering. Military courses can also contain climbing walls and rappelling walls. A very popular place for trekking, valley crossing, rock climbing & rappelling. There are two climbing/rappelling areas. It is also a popular destination for rock climbing and rappelling.