According to Greek mythology, upon his establishment of the newly founded city (polis) of Attica, king Cecrops desired to appoint a patron deity and protector over his new city. Poseidon (Olympic god of the sea, earthquakes, and horses) and Athena (Olympic goddess of wisdom, craft, and war) both desired to lay claim to the ancient Greek city. Appearing before king Cecrops and a gathering of the people of Attica on the Acropolis, it was decided that a contest between the two powerful Olympians would be held. Whoever could bestow the more useful gift to the people of Attica would be declared patron deity and have the city named in his/her honor. Poseidon was the first to present his gift; striking a rock with a powerful blow of his trident, a spring of salt water burst through. Athena came next; as she thrust her spear into the ground of the Acropolis, she knelt down and planted an olive branch in the hole, which quickly grew into Greece's very first moria (olive) tree. King Cecrops and the people of Attica deliberated the usefulness of the gifts. Poseidon's spring made of salt water was not suitable for drinking or much else, yet Athena's precious gift proved to be suitable for an abundance of purposes. Athena was hailed winner of the competition and was crowned patron goddess and protector of the city (polis) of Attica, whose people adopted the name Athens in her honor.
That tree must be very old!