An aerial photo shows Helan Mountain, Northwest China's Ningxia Hui autonomous region, after rainfall on May 9, 2019. The mountain is home to more than 700 species of flora and fauna. [Photo by Su Yong/chinadaily.com.cn]

An aerial photo captures Helan Mountain after rainfall on May 9, 2019, as clouds shroud colorful mountaintops to form a picturesque view. [Photo by Su Yong/chinadaily.com.cn]

An aerial photo captures Helan Mountain after rainfall on May 9, 2019, as clouds shroud colorful mountaintops to form a picturesque view. [Photo by Su Yong/chinadaily.com.cn]

An aerial photo captures Helan Mountain after rainfall on May 9, 2019, as clouds shroud colorful mountaintops to form a picturesque view. [Photo by Su Yong/chinadaily.com.cn]

An aerial photo captures Helan Mountain after rainfall on May 9, 2019, as clouds shroud colorful mountaintops to form a picturesque view. [Photo by Su Yong/chinadaily.com.cn]

An aerial photo captures Helan Mountain after rainfall on May 9, 2019, as clouds shroud colorful mountaintops to form a picturesque view. [Photo by Su Yong/chinadaily.com.cn]