Dictionary of Greek and Roman Geography/Aternus
ATERNUS (Άτερνος: Aterno), a considerable river of Central Italy, flowing into the Adriatic Sea between Adria and Ortona. Strabo correctly describes it (v. p. 241) as rising in the neighbourhood of Amiternum, and flowing through the territory of the Vestini: in this part of its course it has a SE. direction, but close to the site of Corfinium it turns abruptly at right angles, and pursues a NE, coarse from thence to the sea, which it enters just under the walls of Pescara. At its mouth was situated the town of Aternum, or, as it was sometimes called, "Aterni Ostia". In this latter part of its course, according to Strabo (l. c.), it formed the limit between the Vestini and Marrucini; and there is little doubt that this statement is correct, though Pliny and Mela extend the confines of the Frentani as far as the Aternus, and Ptolemy includes the mouths both of that river and the Matrinus in the territory of the Marrucini. (Plin. iii. 12. s. 17; Mela, ii. 4; Ptol. iii. I. § 20.) In the upper part of its course it flows through a broad and trough-like valley, bounded on each side by very lofty mountains, and itself elevated more than 2000 feet above the sea. The narrow gorge between two huge masses of mountains by which it escapes from tins upland valley, must have always formed one of the principal lines of communication in this part of Italy; though it was not till the reign of Claudius that the Via Valeria was carried along this line from Corfinium to the Adriatic. (Inscr. ap. Orell. 711.) Strabo mentions a bridge over the river 24 stadia (3 miles) from Corfinium, near the site of the modern town of Popoli; a point which must have always been of importance in a military point of view: hence we find Domitius during the Civil War (B.C. 49) occupying it with the hope of arresting the advance of Caesar. (Caes. B. C. i. 16.) The Aternus, in the upper part of its course, still retains its ancient name Aterno, but below Popoli is known only as the Fiume di Pescara — an appellation which it seems to have assumed as early as the seventh century, when we find it called "Piscarius fiuvius". (P. Diac. ii. 20.) It is one of the most considerable streams on the E. side of the Apennines, in respect of the volume of its waters, which are fed by numerous perennial and abundant sources.[ E. H. B. ]