a town of Lombardy, in the government of Venice, and delegation of Rovigo; situate between the rivers Po and Adige, in Lat. 45° 3', 22° N. Long. 12° 3', 40° E. This is a very ancient city, and was, at an early period, a seaport of such importance and celebrity as to give name to the sea on which it stood. It is said by some Greek writers to have been of Grecian origin; but the Roman writers, who are of much greater authority, agree in describing it as an Etruscan colony. Under the Romans it appears never to have been of much importance, and after the fall of the Western Empire it rapidly declined. The dykes which protected the surrounding country from inundation were neglected, and it became marshy and unhealthy. The mud and other deposits brought down by the waters of the Po and Adige, caused a gradual extension of the land into the Adriatic; so that Adria ceased to be a seaport, and is now 16 miles from the sea, on whose shores it formerly stood. By the draining of the neighbouring lands, the place has latterly been much improved, and has now begun to revive. It has a population of 10,400, and some trade in grain, cattle, fish, wine, and earthenware; is the seat of a bishopric; and has a museum of Greek and Roman antiquities. A little to the south of the present town, remains of the ancient city have been discovered at a considerable depth. They are all of Roman date, and include part of the ancient walls, ruins of a theatre, baths, and mosaic pavements.