(Source: Yangmingshan National Park Headquarters)

Cising Mountain is located amid the Datun Volcanoe Group and stands the tallest at the rim of the Taipei Basin. Its main peak is 1,120m tall (above elevation) and it began erupting about 700,000 years ago. There was a crater at the peak but it became seven small peaks due to post-eruption erosion. With faults running across the southeast and northwest sides of the mountain, volcanic landforms like hot springs and fumaroles formed. The mountain is in the form of a cone because of lava deposit and aggregated rocks spewed from the volcano. The steep peaks of Chihsing Mountain are the most striking feature of this conical volcano. Shamao Mountain is a round volcanic dome looking like a black gauze cap. As the lava was more viscous when the mountain was formed, it gradually became a tholoid, also known as a cumulo-dome volcano. Shamao Mountain is a parasitic volcano of the Cising Mountain group.