rnmost of which (the Monti Sabini) culminates to the south in the
Monte Viglio (7075 ft.), the central chain in the Monte Terminillo (7260
ft.), and farther south in the Monte Velino (8160 ft.), and the eastern
in the Gran Sasso d'Italia (9560 ft.), the highest summit of the
Apennines, and the Maiella group (Monte Amaro, 9170 ft.). Between the
western and central ranges are the plain of Rieti, the valley of the
Salto (_Himella_), 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 (_Nar_), with its tributaries the Velino
(_Velinus_) and Salto, and the Anio, 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
25 m. distant, such as the Potenza (_Flosis_), Chienti (_Cluentus_),
Tenna (_Tinna_), Tronto (_Truentus_), Tordino (_Helvinus_), Vomano
(_Vomanus_), &c. The Pescara (_Aternus_), which receives the Aterno from
the north-west and the Gizio from the south-east, is more important; and
so is the Sangro.

The central Apennines are crossed by the railway from Rome to
Castelammare Adriatico via Avezzano and Sulmona: the railway from Orte
to Terni (and thence to Foligno) follows the Nera valley; while from
Terni a line ascends to the plain of Rieti, and thence crosses the
central chain to Aquila, whence it follows the valley of the Aterno to
Sulmona. In ancient times the Via Salaria, Via Caecilia and Via
Valeria-Claudia all ran from Rome to the Adriatic coast. The volcanic
mountains of the province of Rome are separated from the Apennines by
the Tiber valley, and the Monti Lepini, or Volscian mountains, by the
valleys of the Sacco and Liri.

3. In the southern Apennines, to the south of the Sangro valley, the
three parallel chains are broken up into smaller groups; among them may
be named the Matese, the highest point of which is the Monte Miletto
(6725 ft.). The chief rivers on the south-west are the Liri or
Garigliano (anc. _Liris_) with its tributary the Sacco (_Trerus_), the
Volturno (_Volturnus_), Sebeto (_Sabatus_), Sarno (_Sarnus_), on the
north the Trigno (_Trinius_), Biferno (_Tifernus_), and Fortore
(_Frento_). The promontory of Monte Gargano, on the east, is completely
isolated, and so are the volcanic groups near Naples. The district is
traversed from north-west to south-east by the railway from S