Calauria (now Póros), a Saronic island (23 sq. km.: 9 sq. mi.) adjacent to the Argolid, and its polis. The town lay near the island's summit (283 m.: 928 ft.); its remains, chiefly Hellenistic, include a probable heroon (see hero-cult) of *Demosthenes (2), who killed himself here.The sanctuary of *Poseidon has Mycenaean tombs, 8th-cent. and later dedications, and cult buildings of c.520–320 bce. It was the focus of the Calaurian *amphictiony, whose members included Hermione, *Epidaurus, *Aegina, *Athens, and Boeotian *Orchomenus (1). The inclusion of Nauplia and Cynurian Prasiae, neither of them autonomous after c.650, implies an early foundation date. Rather than a military, political, or economic union, the amphictiony was probably a cultic association of mainly local, non-Dorian towns: the sanctuary's material apogee is not matched by any known political activity. By *Strabo's time the sanctuary had been sacked by Cilician pirates (see piracy) and the amphictiony no longer existed.