The Great Mandala
Crafted during The Creation of the Vale, the Great Mandala is literally part carving and part permanent sand painting on the flat surface of a high and steep sided mesa. It protects the Vale from any sort of environmental change. I.E. it is always pleasant temperature. There will always be abundant water flowing from the snows on the surrounding mountains. It will always have just enough sun and only just enough ash from the volcanoes will fall to provide just the right nutrients for the soil. And most importantly, it stabilized the earth so there would be no earthquakes and no new volcanic activity in the Vale itself.
Both Empress Carawynne and her daughter Genevieve have shards of the Great Mandala in their foreheads. These shards appear as red gems, approximately the size of a nickel.
Those familiar with such things would recognize that the Great Mandala is a Pattern.