SUNIUM (Σούνιον; mod. Cape Colonna), a cape at the southern extremity of Attica, with a temple of Poseidon upon it, which serves as a landmark for all ships approaching Athens from the east. The rocky promontory on which the temple stands was fortified by a wall with towers, in 413 B.C., as a protection against the Spartans in Decelea; but it was soon after seized by a body of fugitive slaves from the Laurium mines. In the 4th century it was still kept up as a fortress. The temple was shown by an inscription found in 1898 to be dedicated to Poseidon, not, as formerly supposed, to Athena, the remains of whose temple are to be seen about a quarter of a mile away to the north-east; they are of a peculiar plan, consisting of a hall with a colonnade on two sides only. The extant temple on the promontory was probably built in the time of Pericles. It took the place of an earlier one, of similar proportions but built of tufa or “poros” stone. There are still standing nine columns of the south side and two of the north of the peristyle, and one of the antae and an inner column of the pronaos. They are built of local white marble, which has suffered much from the weather. In form they resemble those of the Parthenon and Theseum, but they have only sixteen flutings. Recent excavations have revealed porticoes, a gateway and other buildings, and also the remains of several colossal early statues, the best preserved of which is now in the museum at Athens. The site of Cape Colonna is extolled by Byron, and is the scene of Falconer's “Shipwreck.”  (E. Gr)