(200510) -- DUNHUANG, May 10, 2020 (Xinhua) -- People visit the Mogao Grottoes in Dunhuang, northwest China's Gansu Province, May 10, 2020. The Mogao Grottoes, a renowned UNESCO World Heritage site in northwest China's Gansu Province, reopened on Sunday after being closed for months due to the novel coronavirus disease (COVID-19). At present the well-known tourist site strictly controls daily visits to less than 30 percent of its previous maximum visits, or about 1,800 tickets per day, while the digital center and display room remain closed until further notice. Visitors are required to book tickets online, have their temperatures taken and wear masks during their visits, and group visits will not be accepted yet. (Photo by Sun Zhijun/Xinhua)