In the adjacent area of Attica are the Marathon tumuli, burying mounds in Marathon that house the ashes of the Athenian and Plataean hoplites that were killed in the homonymous battle. Findings from the area and from the battle of Marathon are preserved in the Archaeological Museum of Marathon nearby. In western Attica is Eleusis, where, from as early as 1700 BC up to the 4th century AD, it was the site of the Eleusinian Mysteries, or the Mysteries of Demeter and Kore. At the eastern tip of Attica is Sounion, with the ruins of the Temple of Poseidon.