Pontine Marshes

The Pontine Marshes, termed in Latin Pomptinus Ager by Titus Livius, Pomptina Palus (singular) and Pomptinae Paludes (plural) by Pliny the Elder, today the Agro Pontino in Italian, is an approximately quadrangular area of former marshland in the Lazio Region of Central Italy, extending along the coast southeast of Rome about 45 km (28 mi) from just east of Anzio to Terracina (ancient Tarracina), varying in distance inland between the Tyrrhenian Sea and the Volscian Mountains (the Monti Lepini in the north, the Monti Ausoni in the center and the Monti Aurunci in the south) from 15 km (9.3 mi) to 25 km (16 mi). The northwestern border runs approximately from the mouth of the river Astura along the river and from its upper reaches to Cori in the Monti Lepini.

The former marsh is a low tract of mainly agricultural land created by draining and filling, separated from the sea by sand dunes. The area amounts to approximately 80,000 ha (800 km2; 310 sq mi). The Via Appia, a Roman military road constructed in 312 BC, crosses the inland side of the former marsh in a long, straight stretch flanked by trees. Before then travelers had to use the Via Latina along the flanks of the mountains; Tarracina could not be reached across the marsh.

Further southward along the coast as far as Minturno is another stretch of former coastal marsh called the South Pontino, the largest section being between Terracina and Sperlonga, as far inland as Fondi. It was part of ancient Latium adiectum and still belongs to Lazio. Bordered by the Aurunci mountains, this land is mainly reclaimed as well, but the more frequent incursion of hills permitted more dense settlements. Leaving Terracina, the Via Appia crosses it as well.

The marsh was an extensive alluvial plain at approximately sea level (some above, some below) created by the failure of the streams draining the mountains to find clearly defined outlets to the sea through the barrier dunes. Above sea level it was a forested swamp; below, mud flats and pools. Sparsely inhabited throughout much of their history, the Pontine Marshes were the subject of extensive land reclamation work performed periodically. The tribe of the Volsci began with minor draining projects in the vicinity of Tarracina in connection with their occupation of it in the pre-Roman period.

The road proved difficult to keep above water. Under Augustus a compromise was reached with the construction of a parallel canal. The part of the marsh above sea level was successfully drained by channels and new agricultural land of legendary fertility came into being. Whenever the channels were not maintained the swamp reappeared. Meanwhile frequent epidemics of malaria at Rome and elsewhere kept the reclamation issue alive. Under Benito Mussolini's regime in the 1930s the problem was nearly solved by placing dikes and pumping out that portion of the marsh below sea level. It continues to need constant maintenance. Italian confidence in the project was so high that the city placed by Mussolini in 1932 in the center of the marsh, Latina, became the capital of a new province, Latina.