The Acropolis is a rocky outcrop rising 150 m (490 ft) above sea level. It is not the highest hill in downtown Athens, but it was the most convenient for habitation and defence due to its flat surface and the presence of freshwater springs. It is impossible to overstate its cultural significance for the Athenians. The Acropolis was the site of the divine contest between Athena and Poseidon for control of Athens (Athena brought forth an olive tree and won the right to name the city after herself). The early kings of Athens (some of whom were half men and half serpents) erected their palaces here and taught the Athenians reading, writing, marriage, and ceremonial burial. As for their daughters, they were always willing to sacrifice themselves for the city's survival, falling to their deaths from the battlements.