SELEUCIA PIERIA, the seaport of Antioch, on the north side of the Bay of Antioch, at the foot of a mountain anciently called Coryphaeum, now Jebel Musa, about 8 miles N. by W. of the mouth of the Oronites. It was strongly fortified with a double line of defences, connected with a castellated fort on the summit of the hill. The harbour was well suited for the galleys of the ancients, and of its substantial piers considerable portions still remain. Besides the outer port, formed by two piers, there was an inner basin, to which an entrance was cut through the solid rock, and defended by a tower on each side. For supplying water to the harbour a great work was constructed, consisting partly of tunnels and partly of deep cuttings, for a distance of 1088 yards. Of all these structures, as well as of several temples, an amphitheatre, and many tombs in the rocks, considerable remains are yet to be seen, confirming the accuracy of the description that Polybius gives of the city. Seleucia was a place of much importance in the wars between the Syrian and Egyptian monarchs. It was taken by Ptolemy Euergetes during his invasion of Syria, and retained by the Egyptians until the time of Antiochus the Great. This monarch led an army against the city, and by taking the suburb and arsenal, forced it to surrender, about 220 B.C. Seleucia afterwards passed into the hands of the Romans, and received from Pompey the dignity of a free city. It is noted in Scripture history as the place where Paul set sail on his first missionary journey (Acts xiii. 4).