Cows cross a river in Arxan, Hinggan League, a city in North China's Inner Mongolia autonomous region, on Dec 14. While the air temperature in the local area is currently below freezing, this particular river never freezes. This is due to volcanic activity underground which produces an abundance of geothermal energy –– keeping the water temperature above freezing. At times, there is even steam visible, rising from the flowing water. [Photo/northnews.cn]