If you continue past the turnoff to Mysterious Valley, you will eventually arrive at Doucilin. The view here is superb - looking down into the valley below. It also faces northeast, and so is cooler in the summer. It also does not get wet as easily as the other walls. Most climbs here are extremely difficult, as you can determine by the 90-degree overhang out of the cave at the bottom. Yuji Hirayama attempted a project here back in 2003.
From the Assembly Field, continue up the short hill until you reach a branch in the trail. To the left is Mysterious Valley, and straight - past the boulder and over many caves - leads to Doucilin. Just continue along the trail, staying below the crest of the ridge, until you come to the clearing, the stone, and the view.