The Nile was regular, navigable, and benign, making for one of the safest and richest agricultural areas in the world. Each summer, the river flooded the fields at precisely the right time, leaving behind nutrient-rich silt for planting season. Planting was so easy that Egyptians just tossed seeds around the silty earth and then let their cattle or pigs walk on it to press the seeds into the ground, and then boom, grain and figs and wheat and pomegranates and melons and joy. Unlike most river valley civilizations, Egyptian communities existed only along the Nile, which was navigable enough to get valuable resources downstream, from timber to gold, which the Egyptians considered the divine metal, thereby introducing an idea that would eventually culminate in Mr. T. The Nile was also easily tamed. While other river valley civilizations needed complicated and labor-intensive hydraulic engineering projects to irrigate crops, the Nile was so chill that Egyptians could use a simple form of water management called basin irrigation, in which farmers used floodwaters to fill earthen basins and canals for irrigation. In short, the awesomeness of the Nile meant Egyptians could create big food surpluses with relatively little work, allowing time and energy for some pretty impressive projects. Also, the Nile may help explain ancient Egypt's general optimism.