People take photos at the Blue Moon Valley in Lijiang, southwest China's Yunnan Province, Dec. 10, 2019. (Xinhua/Yang Zongyou)

Tourists visit the Blue Moon Valley in Lijiang, southwest China's Yunnan Province, Dec. 10, 2019. (Xinhua/Yang Zongyou)

Tourists visit the Blue Moon Valley in Lijiang, southwest China's Yunnan Province, Dec. 10, 2019. (Xinhua/Yang Zongyou)

Tourists visit the Blue Moon Valley in Lijiang, southwest China's Yunnan Province, Dec. 10, 2019. (Xinhua/Yang Zongyou)

Photo taken on Dec. 10, 2019 shows the scenery of Blue Moon Valley in Lijiang, southwest China's Yunnan Province. (Xinhua/Yang Zongyou)

Photo taken on Dec. 10, 2019 shows the scenery of Blue Moon Valley in Lijiang, southwest China's Yunnan Province. (Xinhua/Yang Zongyou)

Photo taken on Dec. 10, 2019 shows the scenery of Blue Moon Valley in Lijiang, southwest China's Yunnan Province. (Xinhua/Yang Zongyou)

Photo taken on Dec. 10, 2019 shows the scenery of Blue Moon Valley in Lijiang, southwest China's Yunnan Province. (Xinhua/Yang Zongyou)

Tourists pose for photos at the Blue Moon Valley in Lijiang, southwest China's Yunnan Province, Dec. 10, 2019. (Xinhua/Yang Zongyou)