Photo taken on Sept. 4, 2020 shows a sightseeing vehicle running by the Caka Salt Lake in Wulan County, northwest China's Qinghai Province.Photo:Xinhua

Tourists visit the Caka Salt Lake in Wulan County, northwest China's Qinghai Province, Sept. 4, 2020.Photo:Xinhua

Tourists visit the Caka Salt Lake in Wulan County, northwest China's Qinghai Province, Sept. 4, 2020.Photo:Xinhua

Aerial photo taken on Sept. 4, 2020 shows a sightseeing vehicle running by the Caka Salt Lake in Wulan County, northwest China's Qinghai Province.Photo:Xinhua

Aerial photo taken on Sept. 4, 2020 shows a sightseeing vehicle running by the Caka Salt Lake in Wulan County, northwest China's Qinghai Province.Photo:Xinhua

A tourist is seen at the Caka Salt Lake in Wulan County, northwest China's Qinghai Province, Sept. 4, 2020.Photo:Xinhua