The fourth geographic feature was the high desert, a barren area that was crossed only by trade caravans or organized groups searching for stone and unstructured resources, such as calcite, gold, copper, amethyst, carnelian, and diorite. Individual oases excavated in the high desert were cultivated to grow valuable crops like grapes and dates. These areas were essential links in trade with more last areas and were as well used as properties to house exiled captives.
