municipalities were detached to form the Province of Isernia, established under Law No. 2 of February 1970. Geography The Province of Campobasso is situated in eastern Italy on the Adriatic coast. It is bordered to the north by the Province of Chieti in Abruzzo, to the south-east by the Province of Foggia in Apulia, to the south by the Province of Benevento and the Province of Caserta in Campania, and to the west by the Province of Isernia. The terrain is varied extending from the mountainous Apennines, down through hills, lakes and inland rivers to the Adriatic coast. The territory is crossed by the river valleys of the Trigno (85 km), Biferno (84 km) and Fortore (110 km), flanked by hills and mountains. Other rivers of note include the Tammaro (78 km), the Saccione (33 km), the Sinarca (26 km), and the Sassinora (7 km). All flow into the Adriatic with the exception of the Tammaro. The central Valle del Biferno includes the Lago di Guardialfiera, to the east of Castelmauro. The other lake of note is Lago di Occhito to the south east of Sant'Elia a Pianisi. The provincial capital of Campobasso lies in the south of the province, north of the Matese mountains, one of the three main mountain ranges in the Molise region. On the coast, the principal towns are Termoli and Campomarino. Demography The population of the province rose between 1861 when there were 229,393 inhabitants and 1951 when it totalled 289,577. Over the next 20 years it fell back to 227,641 (1971) after which it rose once again to 238,958 in 1991. It has since undergone a slight reduction to 225,622 inhabitants in 2016. As of 1 January 2014, the most populous communes (comuni) in the province are Campobasso (49,392), Termoli (33,478), Bojano (8,125), Campomarino (7,723), Larino (6,910), Montenero di Bisaccia (6,798), Guglionesi (5,422), Riccia (5,332), San Martino in Pensilis (4,827) and Trivento (4,788). Acquaviva Collecroce, with a population of 714, is the largest of three municipalities in the province where the inhabitants are of Croatian origin. It is believed they arrived at the end of the 15th century from Bosnia-Herzegovina and Croatia. They still speak a Croatian dialect as well as Italian. The other two municipalities with inhabitants of Croatian origin are San Felice del Molise and Montemitro. All three municipalities lie to the north of the city of Campobasso. As of 1 January