A quest to explore some of the most spectacular ancient cities in human history - and figure out why people abandoned them. Investigating across the centuries and around the world, Newitz explores the rise and fall of four ancient cities, each the center of a sophisticated civilization: the Neolithic site of Çatalhöyük in Central Turkey, the Roman vacation town of Pompeii on Italy's southern coast, the medieval megacity of Angkor in Cambodia, and the indigenous metropolis Cahokia beside the Mississippi River