1911 Encyclopædia Britannica/Poros
POROS, or Poro (“the Ford”), an island off the east coast of the Morea, separated at its western extremity by only a narrow channel from the mainland at Troezen, and consisting of a mass of limestone rock and of a mass of trachyte connected by a slight sandy isthmus. The town looks down on the beautiful harbour between the island and the mainland on the south.
The ancient Calauria, with which Poros is identified, was given, according to the myth, by Apollo to Poseidon in exchange for Delos; and it became in historic times famous for a temple of the sea-god, which formed the centre of an amphictyony of seven maritime states—Hermione, Epidaurus, Aegina, Athens, Prasiae, Nauplia, and Orchomenus. Here Demosthenes took sanctuary with “gracious Poseidon,” and, when this threatened to fail him, sought death. The building was of Doric architecture and lay on a ridge of the hill commanding a fine view of Athens and the Saronic Gulf, near the middle of the limestone part of the island. The site was excavated in 1894, and traces of a sacred agora with porticoes and other buildings, as well as the temple, have been found. In the neighbourhood of Poros-Calauria are two small islands, the more westerly of which contains the ruins of a small temple, and is probably the ancient Sphaeria or Hiera mentioned by Pausanias as the seat of a temple of Athena Apaturia. The English, French, and Russian plenipotentiaries met at Poros in 1828 to discuss the basis of the Greek government.
See Chandler, Travels; Leake, Morea; Le Bas, Voyage archéologique; Curtius, Peloponnesos; Pouillon-Boblaye, Recherches; Bursian, Geographie von Griechenland; Rangabé “Ein Ausflug nach Poros,” in Deutsche Revue (1883); and S. Wide, in Mitteilungen d. deutsch. Inst. Athen. (1895), vol. xx.