Guanyin Volcano rises in the northwest of Taipei Basin. The location straddles the boundaries among Wugu, Bali and Linkou. It is in direct view with the Datun Volcanic Group across the Tamsui River.  The entire extent of Guanyinshan comprises 18 peaks in a chain, entirely of igneous rocks. The view is quite spectacular. When seen at a distance from the northern bank of the Tamsui River, the profile resembles that of Bodhisattva (Avalokiteshvara, Guanshiyin, the goddess of Mercy) lying at rest by the Tamsui River. On the mountain, the ocean is in full view. The peaks of Guanyinshan are frequently enshrouded in mist and cloud, and “Misty Precipices” was one of eight scenic attractions at Tamsui. The “Tough Guy’s Peak” is a straight climb of 612m to reach the mountaintop for a good view of the sea.
Guanyinshan comprises a number of volcanoes occurring most northwestward of the Datun Group of volcanoes. The volcanoes were formed by volcanic activities resulting from subduction of the Philippine sea plate underneath the Eurasian continental plate. Volcanic eruption started about 600,000 years ago and has ceased about 200,000 years ago. Lava from the eruption cooled off and consolidated into basalt and andesite. Andesites are harder, denser and more compact than basalt, and have been used since the Qing dynasty in construction and sculptures. This material, commonly called Guanyin Stone, has been the main source of dimension stones in Taiwan in the past 100 years. 

NTU Digital Archives of Geosciences Department
National Taiwan University