TRERUS(Τρῆρος, Strab.: Sacco), a river of Latium, and one of the principal tributaries of the Liris ( Garigliano), into which it discharges its waters close to the ruins of Fabrateria. (Strab. 5. p. 237.) Its name is mentioned only by Strabo, but there is no doubt of its identification: it is still called the Toleroin the lower part of its course, near its junction with the Garigliano, but more commonly known as the Sacco.It has its sources in the elevated plain which separates the mountains about Praeneste from the Volscian group; and the broad valley through which it flows for above 40 miles before it joins the Gariglianomust always have formed a remarkable feature in this part of Italy. Throughout its extent it separates the main or central ranges of the Apennines from the outlying mass of the Monti Lepinior Volscian mountains, and hence it must, from an early period, have constituted one of the natural lines of communication between the plains of Latium proper (the modern Campagna di Roma) and those of Campania. After the whole district had fallen under the power of Rome it was the line followed by the great highroad called the Via Latina. [VIA LATINA]
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