Tourists visit Zhuokeji Tusi heritage site in Ma'erkang, Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province, June 6, 2020. (Xinhua/Gao Jianjun)

Aerial photo taken on June 6, 2020 shows a view of Zhuokeji Tusi heritage site in Ma'erkang, Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province. (Xinhua/Zhang Chaoqun)

A visitor tours Zhuokeji Tusi heritage site in Ma'erkang, Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province, June 6, 2020. (Xinhua/Gao Jianjun)

Tourists visit Zhuokeji Tusi heritage site in Ma'erkang, Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province, June 6, 2020. (Xinhua/Gao Jianjun)

Tourists visit Zhuokeji Tusi heritage site in Ma'erkang, Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province, June 6, 2020. (Xinhua/Gao Jianjun)

Tourists visit Zhuokeji Tusi heritage site in Ma'erkang, Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province, June 6, 2020. (Xinhua/Gao Jianjun)