Herdsmen sacrifice at an obo (stone pile for offering sacrifices to the gods) to pray for good weather during the nomadic migration on the Ar Horqin grassland in Chifeng City, north China's Inner Mongolia Autonomous Region, June 1, 2019. Yearly nomadic grazing is still a tradition for people live on the Ar Horqin grassland, where was listed of National Important Agricultural Heritage Systems in 2014. For a long time, herdsmen would decide the route and time of yearly nomadic grazing according to the growth of grassland. (Xinhua/Peng Yuan)