"adventure treks" that include both trekking and climbing options. Adventurous treks and hikes up mountains take place, with expeditions to local mountains and hills. There are island tours, diving, fishing, plantation trips, treks and other tourism related activities. Steep climbs up elongate mountain ranges alternate with long treks across flat, dry deserts. There are also hiking clubs like Hill Top Treks and The Bog Trotters. Nature trails and treks are also popular. Some levels include vehicle-themed portions such as rafting, jeep treks, and mine cart chases. Fishing is popular, as are jungle treks, waterfalls and caves. Group rides are common, especially on longer treks. Elephants can sustain injuries related to giving rides, or going on treks, with tourists. The Great Himalaya Trail is considered to be one of the world's most difficult treks. Young's expedition was one of the largest and one of the best organized westward treks. "Encarta 2000" and later had "Map Treks", which were tours of geographic features and concepts. Conservationists live in staff camps and lead conservation projects for treks passing through their camp. Some cameleers employed Aboriginal men and women to assist them on their long desert treks.