Pingshanhu Grand Canyon is Zhangye's rougher, less polished counterpart to the famous Danxia colour hills. Instead of rainbow ridges seen from viewing platforms, you get eroded red walls, narrow ravines, and routes that drop you down into the canyon floor before climbing back out.
It is a real half-day outing from Zhangye, and the distances inside the scenic area are easy to underestimate. Wear shoes with grip, carry water, and avoid the hottest part of summer days if you can. The reward is a landscape that feels more physical than scenic: you walk through the geology rather than just photographing it from above.