Blue Sky Concave is the commanding height of Huihang Ancient Road, more than 1,000 meters above sea level, because the two peaks are "concave" font, blue sky and white clouds are embedded in it, so it is named. On the blue sky concave, the eyes suddenly open, the mountains are picturesque. Blue Sky concave is the most open place of Huihang Ancient Road, becoming a place of camping and tying for travel friends.