Wushanding Mud Volcano is located in the Cishan Fault Zone. There is abundant natural gas and groundwater beneath the ground surface. Due to the soft mudstones, natural gas mixes with groundwater and mud during eruption, thereby forming thick mudflows. The deposition of mudflows at fumaroles gradually results in typical mud cones after a long period of time. In March 1992, the Council of Agriculture under the Executive Yuan proclaimed that this place became the Wushanding Mud Volcano Nature Reserve pursuant to the Cultural Heritage Preservation Act. With an area of 4.89 hectares, this nature reserve is the smallest in Taiwan, but it is also the largest and best preserved mud volcano reserve in the country.