Where was Yanmenguan in Hu Jun's Eight Dragons filmed?

Deep in the mountains of Xiaonan new castle, the crew set up locations such as Yanmenguan and Yeluhongji's tent camp, and photographed Qiao Feng, Duan Yu, Xu Zhu, Wang Yuyan, Ajun, A Zi, Zhong Ling, Mu and nearly 100 people's "Shaolin disciples, Beggars' disciples, Lingjiu Palace disciples and Qidan Army" resting outside Yanmenguan, as well as group scenes of Qiao Feng and Yeluhongji in tents.