The ice-free stream in Arxan, Hinggan League, Inner Mongolia autonomous region. [Photo/people.cn]

Located in eastern Inner Mongolia’s Hinggan League, Arxan is usually covered in snow during the freeze-up winter. But one stream flows continuously throughout the season, attracting tourists and photographers to the site.

As part of the Khalkh River (or Khalkhyn Gol), the ice-free stream is formed because of abundant geothermal energy generated by volcanic activity underneath the ground. The volcanic activity prevents the stream from freezing during the bitter winter; instead it often leaves a vapor visible on the surface due to the heat below.

Originating from the West Greater Hinggan Mountains, the Khalkh River eventually splits into two distributaries. It also marks the boundary between China and Mongolia.