Aerial photo taken on July 26, 2020 shows hot air balloons flying over Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Aerial photo taken on July 26, 2020 shows hot air balloons flying over Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Aerial photo taken on July 26, 2020 shows hot air balloons flying over Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Aerial photo taken on July 26, 2020 shows hot air balloons flying over Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Photo taken on July 27, 2020 shows a view of the Danxia landform at Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Photo taken on July 27, 2020 shows a view of the Danxia landform at Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Photo taken on July 27, 2020 shows a view of the Danxia landform at Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Photo taken on July 27, 2020 shows a view of the Danxia landform at Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)

Photo taken on July 27, 2020 shows a view of the Danxia landform at Zhangye Geopark in Zhangye, northwest China's Gansu Province. The geological park was approved as a Global Geopark by the Executive Board of the United Nations Educational, Scientific and Cultural Organization (UNESCO) at its 209th session on July 7, 2020. (Xinhua/Fan Peishen)