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

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

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

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.

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.

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

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

Aerial photo taken on Sept. 4, 2020 shows the view of the Caka Salt Lake in Wulan County, northwest China's Qinghai Province.