Tourists visit snow-covered Pingyao Ancient City in north China's Shanxi Province, Jan. 5, 2020. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

Aerial photo taken on Jan. 5, 2020 shows the snow scenery of Pingyao Ancient City in north China's Shanxi Province. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

Tourists visit the snow-covered Pingyao Ancient City in north China's Shanxi Province, Jan. 5, 2020. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

Photo taken on Jan. 5, 2020 shows the snow scenery of Pingyao Ancient City in north China's Shanxi Province. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

A man rides a bicycle in snow in Pingyao Ancient City, north China's Shanxi Province, Jan. 5, 2020. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

Tourists visit snow-covered Pingyao Ancient City in north China's Shanxi Province, Jan. 5, 2020. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

Aerial photo taken on Jan. 5, 2020 shows the snow scenery of Pingyao Ancient City in north China's Shanxi Province. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua

Tourists visit the snow-covered Pingyao Ancient City in north China's Shanxi Province, Jan. 5, 2020. Founded in the 14th century, the Ancient City of Pingyao is an exceptionally well-preserved example of a traditional Han Chinese City, which was named a World Heritage Site by UNESCO in 1997. Photo:Xinhua