Historical heritage sites open to public in France to mark European Heritages Days

People visit the Paris Opera Theater during the European Heritage Days in Paris, France, Sept. 21, 2019. Historical heritage sites are open to public this weekend in France to mark the European Heritages Days, which are held in September each year. The European Heritages Days are the most widely celebrated participatory cultural event shared by the citizens of Europe. (Xinhua/Gao Jing)