Houzishan (Monkey Mountain) is a river terrace along the Xiuguluan River that is located on the east side of the Dewu river terrace in Ruisui Township, Hualien County. Its traditional name is Kawasan, which means a place where gods and ghosts appear. Therefore, it is also called Ghost Mountain. It is said that macaques came here to forage in the past. Xiuguluan River is the largest river in eastern Taiwan, with a total length of about 104 km. In the process of cutting through the coastal mountains, many steep canyons have also been formed, resulting in developed meanders and river terraces, such as Dewu River Terrace, Monkey Mountain, and Chimei River Terrace. This makes an excellent classroom for observing geology or topography.