Roman Republic: Physical Geography of Italy

Italy is a long, narrow peninsula jutting into the Mediterranean Sea towards the coast of North Africa. Physically, Italy can be divided into four regions: the Alps (some of its peaks are over 3000 metres high) along the northern border; the North Italian Plain on the sides of the Po River, the largest area of flat plain in Italy; the Apennines (all of its peaks are below 3000 metres) together with the  coastal plains on either side extending the full length of Italy; and a number of islands (≈seventy) including the two largest, Sicily (26,000 km²) and Sardinia (24,000 km²).

The Po River (northwest) and the Adige (north) rise in the Alps and flow eastwards into the Adriatic Sea. The Arno (north), Tiber (central) and the Volturno (further south), rise in the Apennines and flow westwards into the Tyrrhenian Sea (part of the Mediterranean Sea). Reno (north) rises in the Apennines, but flows eastwards into the Adriatic Sea.

The central Alps have a number of passes, including the Brenner Pass in the east; and where its southern foothills meet the North Italian Plain is (from west to east) a string of lakes – Maggiore, Como, Iseo and Garda. North of the Po River (from west to east) are Piedmont (Turin), Lombardy (Milan) and Venetia (Venice) on the northeast coast. South of Lombardy and Veneto is Emilia-Romagna (Bologna), with its base on the Adriatic coast. Northwest on the north coast of the Tyrrhenian Sea is narrow crescent-shaped Liguria (Genoa).

On the west coast southwest of Emilia-Romagna is Tuscany (Florence), mountainous through most of the region except in the Arno Valley. To the southeast in Umbria (Perugia), the eastern mountains descend westwards to the Tiber Valley and Lake Trasimene. East is Marche (Ancona), and southwest is Lazio (Rome). In the hills of northern Lazio the lakes Bracciano and Bolsena fill the craters of extinct volcanoes. 

On the west coast south of Lazio, much of Campania (Naples) is mountainous; on the east coast Abruzzi (L’Aquila) and Molise (Campobasso) are mostly mountainous or hilly. At Italy’s ‘foot’ the ‘heel’ is Apulia (Bari), the ‘instep’ is Basilicata (Potenza) and the ‘toe’ is Calabria (Catanzaro).

The ancient regions of Italy can be divided into three groups and be compared with those of the three modern groupings.