When Joy and Harvey the other week, I joined them on a trip to a nearby section of the great wall. Do you see the high bit in the center-top of the picture on the left? We had just walked from up there. The unevenness of the step spacing was surprising and made for some slow going, but now we can say, "I climbed the great wall!" Well... part of it at least.
The picture on the right is the view from the tower at the high-center of the left-hand side picture.