Mount Sinabung, Indonesia. (Credit: Yosh Ginsu/Unsplash) Ancient Egypt was the most powerful civilization in the world for a time. The monuments built by laborers to honor pharaohs stand to this day, testament to the vast resources at their command. But the architectural excess hid a crippling weakness. Egypt sits in the middle of a vast desert. To support a population that numbered in the millions, large-scale agriculture was vital, and for that you need water, and therefore, the Nile. The river was so important to the Egyptians that they still celebrate a two-week long festival during the yearly floods. It was thought to be fed by the tears of Isis. Even small fluctuations in flood levels could bring famine or catastrophe.