The name 'Xiaoyoukeng' translates literally to 'small oil pit', referring to the historical observation of bubbling mud pools that resembled boiling oil.
The fumaroles here are part of the Datun Volcano Group, which remains one of the most active geothermal areas in Taiwan.
Sulfur deposits at the site are formed through the chemical reaction of volcanic gases with the surrounding rocks.
The temperature of the steam emitted from the vents can reach nearly 100 degrees Celsius.
The area serves as a primary monitoring station for the seismic and volcanic activity of the Qixing Mountain system.
Xiaoyoukeng is a post-volcanic geological site located within Yangmingshan National Park, characterized by active fumaroles, sulfur crystals, and hot springs. The area is situated on the northwestern slope of Qixing Mountain at an elevation of approximately 800 meters. Visitors can observe distinct volcanic landforms, including sulfur vents that emit continuous steam and volcanic gas. The site features a well-maintained walking trail that leads from the visitor center through the geothermal landscape. Erosion and seismic activity have sculpted the surrounding terrain, revealing layered volcanic rock and deposits. The environment is notably rich in sulfuric minerals, which have inhibited extensive vegetation growth directly around the vents. The visitor center serves as an educational hub providing exhibits on the tectonic history of the Taipei basin. The site is a key geothermal observation point in Taiwan, representing the cooling stage of the Datun Volcano Group.
The observation deck directly overlooking the main fumarole area, which captures the steam vents against the backdrop of the mountain ridge.
Wear a mask if you are sensitive to strong sulfur odors, which can be intense depending on wind direction.
Stick strictly to the marked wooden boardwalks to avoid contact with high-temperature ground and acidic soil.
Bring a windbreaker or light jacket, as the altitude and exposed location lead to rapid temperature drops and high winds.
Attempting to touch the steam or water in the vents, which is extremely hot and corrosive.
Stay on designated paths at all times for personal safety; do not touch rocks or collect sulfur samples.
