Tourists take photos in front of the Mati Temple Grottoes in Zhangye, Northwest China's Gansu Province, on June 23, 2025. Carved during the Northern Liang period of the Sixteen Kingdoms era (304-439), the Mati Temple Grottoes are regarded as one of the three great Buddhist art treasure troves of the Hexi Corridor, alongside the Mogao Caves in Dunhuang and the Yulin Caves in Guazhou. It is the only grotto complex in China where the walkways are built entirely within the cliff face. Photo: VCG