Look how steep that thing is! Yeah, that's the path up. There are no switchbacks or anything. I shot it at 17mm (1.6x crop factor), so there's some perspective distortion, but to give some perspective, that little wedge section between the turrets with people standing on it, is flat. That next section up looks like it's damn near 90 degrees! Imagine being in the Chinese army back in the day. Running up that thing in full armor and weapons? In the icy winter? Screw it, I'd just let the Mongolians through. =P
If you missed the first Great Wall photo, the valley and the opposite mountains are this clear thanks to the RAW format and the digital darkroom.