Among them, Alishan consists of Shishui Mountain, Jianshan Mountain, Datashan Mountain, Xiaotashan Mountain, Zhushan Mountain, Wanshou Mountain and Duishan 18 peaks with an altitude of over 2000 meters. Among them, Datashan Mountain is the highest, with an altitude of 2,663 meters. Because there are many high mountains over 3,000 meters in Taiwan Province Province, Alishan is not outstanding compared with Yushan next door. However, separated by a Nanzi Xianxi, 20 kilometers away from Yushan, there is still a majestic momentum that echoes from afar. Alishan starts from the south bank of Zhuoshui River in Nantouji in the north and reaches Jiguan Mountain in Kaohsiung Rock Nest in the south. The ridge vein is generally NNE-SW, with a length of about 250 kilometers and an average height of 2500 meters. Because the big fault passes through the east side of Alishan Mountain range, the east slope is steep and the west slope is gentle. Most mountain strata are composed of sandstone, shale and sand shale interbeds with younger geological age. On the other hand, the geological age of the adjacent Yushan Mountains is older. In recent years, some geologists have carefully inferred that Alishan was originally located on Yushan Mountain according to the continuous characteristics of geological times and the geological evidence of many large faults between the two mountains. Later, it was strongly squeezed by the eastern plate, which led to the fracture of two connected mountains. After the younger rocks above broke, they slipped westward, forming today's Alishan Mountains, while the older rocks below formed the Yushan Mountains.