I went with a hiking group to Chichengxian in the Zhangjiakou area to hike 29 km at an altitude of 1.000 – 1.500m. We arrived there by bus at 11 am. Before 6 pm we had to finish the trail to avoid having to climb the steep path in the dark. Unfortunately, we had a lot of fog in form of heavy air pollution, which made wide views nearly impossible. Taking photos was also quite a challenge due to time constraints. We were almost running the trail to finish in time with only very short breaks.