<P> The west border of the Umbrian - Marchean Apennines (or "Umbro - Marchean") runs through Cagli . They extend south to the Tronto River, the south border of the ONA . The highest peak, Monte Vettore, at 2,478 m (8,130 ft), is part of the Monti Sibillini, incorporated into Parco Nazionale dei Monti Sibillini . Further inland is Parco Sasso Simone e Simoncello and further south Parco naturale regionale Gola della Rossa di Frasassi, in which are the Gola della Rossa ("Canyon of the Red") and Frasassi Caves . The Italian Park Service calls it the "green heart" of Italy . The region is heavily forested, such as the Riserva Naturale Statale Gola del Furlo, where Furlo Pass on the Via Flaminia is located . Both the Etruscans and the Romans constructed tunnels here . </P> <P> The Abruzzi Apennines, located in Abruzzo, Molise (formerly part of Abruzzo) and southeastern Lazio, contain the highest peaks and most rugged terrain of the Apennines . They are known in history as the territory of the Italic peoples first defeated by the city of Rome . Coincidentally they exist in three parallel folds or chains surviving from the orogeny . These extend in a northwest - southeast direction from the River Tronto to the River Sangro, which drain into the Adriatic . The coastal hills of the east extend between San Benedetto del Tronto in the north and Torino di Sangro in the south . </P> <P> The eastern chain consists mainly of the southern part of the Monti Sibillini, the Monti della Laga, the Gran Sasso d'Italia Massif and the Majella Massif . Among them are two national parks: Gran Sasso e Monti della Laga National Park and Majella National Park; and the Regional Park of the Monti Simbruini . Gran Sasso contains Corno Grande, the highest peak of the Apennines . </P> <P> Other features between the western and central ranges are the plain of Rieti, the valley of the Salto, and the Lago Fucino; while between the central and eastern ranges are the valleys of Aquila and Sulmona . The chief rivers on the west are the Nera, with its tributaries the Velino and Salto, and the Aniene, both of which fall into the Tiber . On the east there is at first a succession of small rivers which flow into the Adriatic, from which the highest points of the chain are some 20 km distant, such as the Tronto, Tordino, Vomano and others . The Pescara, which receives the Aterno from the north - west and the Gizio from the south - east, is more important; and so is the Sangro . </P>

These mountains are east of rome and south of venice italy