ARTA, GULF OF (the Ambracius Sinus of the ancients), a gulf of the Ionian Sea, in Lat. 39. N. Long. 21. E., having on the north Albania, and on the south and east Acarnania. Its length is 25, and its greatest breadth 10 miles, with a depth varying from 13 or 14 to 36 fathoms. Its entrance is only 700 yards across, outside of which is a bar composed of gravel, coarse sand, and sea-weed, with fifteen feet of water when shallowest. The north shore is for the most part low and swampy, and has encroached considerably on the water: the southern shore consists of high land with bold promontories, clothed with rich and extensive forests. It has been long celebrated for its excellent fish, of which the red and gray mullet are the most plentiful; and soles and eels also abound. The famous battle of Actium, which decided the fate of Augustus and Mark Antony, was fought near the entrance of this gulf in B.C. 31.