An unfrozen section of the Halha River in the city of Arxan of Hinggan League, north China's Inner Mongolia Autonomous Region, Nov. 20, 2019. (Xinhua/Peng Yuan)

It is amazing that it never freezes, even during the coldest time of winter.

HINGGAN LEAGUE, Nov. 21, 2019 (Xinhua) -- Despite Arxan's frigid winter cold, this geothermally-affected, 20-kilometer section of the Halha River never freezes even when the temperature drops to as low as minus 40 degrees Celsius.

An unfrozen section of the Halha River in the city of Arxan of Hinggan League, Nov. 20, 2019. (Xinhua/Peng Yuan)

An unfrozen section of the Halha River in the city of Arxan of Hinggan League, Nov. 20, 2019. (Xinhua/Peng Yuan)

A herd of cattle drink water in an unfrozen section of the Halha River in the city of Arxan of Hinggan League, Nov. 20, 2019. (Xinhua/Peng Yuan)

Frost-covered plants by an unfrozen section of the Halha River in the city of Arxan of Hinggan League, Nov. 20, 2019. (Xinhua/Peng Yuan)

A herd of cattle are seen near an unfrozen section of the Halha River in the city of Arxan of Hinggan League, Nov. 20, 2019. (Xinhua/Peng Yuan)

An unfrozen section of the Halha River in the city of Arxan of Hinggan League, Nov. 20, 2019. (Xinhua/Peng Yuan)■