That's Brad starting out at the bottom of the great wall. Are we going to that building? No... that's the first of 4 (or 5 - I lost count). If you can make out a tiny, tiny building shape over the top of that tree to the left, that's where we were headed.
And that is Sierra going down...down... down. Yes, it was that steep and that far. I couldn't look ahead as we went down, just had to look at the step in front of me. And the steps are all different heights too - just to add to add to the fun!