The town's name derives from the Latin "saepes" (hedge) and "Saepio" (to surround), from which comes "Saepinum". Municipality in the province of Campobasso, situated on a hill covered with woods, on the edge of the Matese massif, on the border with the Campania region, the historical center of Sepino retains its original medieval structure with narrow streets and typical fountains. Once surrounded by thick walls, it still preserves some of the watchtowers and three of the four entrance gates to the main centre. It is famous for its thermal springs suitable for the treatment of kidney illnesses.
The earliest traces of human presence in the area date back to the Neolithic period. In the III century B.C. it became an important center of the Samnites, which was destroyed during the Third Samnite War. It was a bishopric between the V century till the submission to the Lombard rule, and subsequently assumed the name of Saepinum Altilia and was annexed to Castaldato of Bojano. After several disastrous natural events, the town depopulated and only thanks to the Benedictine monks from Benevento and their persistence in agricultural activities, the centre experienced a new development. The original centre, located in a flat area, was subject to continuous Saracen raids, obliged the local inhabitants to abandon it in year 882 and rebuild a new one (Castellum Saepini), more inland. From the XI century until the first half of the XVIII, several noble families succeeded to the government of the territory and belonged to the County Bojano, to the Barony of the family de Molisio, to the Count of Altavilla, to the Carafa and to the Della Leonessa.
- the XII century Church of Santa Cristina, which has undergone several changes over the centuries. It features a Latin cross plan with three naves; the ceiling of the central one is decorated with paintings of Trivisonno, as well as the dome that covers the area of main altar. Inside are preserved: the cave of Santa Cristina, the Treasure Room, a XIX century wooden Choir, the Way of the Cross of Legnaghi, a XVII century stoop and baptismal font and a silver bust depicting the Saint. It is flanked by a bell tower with a very curious exterior;
- the Church of San Lorenzo with its Romanesque bell tower;
- the Church of Santa Maria Assunta;
- the former Church of Santo Stefano;
- the Convent of the Holy Trinity;
- the Church of the Purgatory;
- the remains of the antique Saepinum, an inhabited area since the Augustan age. Still visible and recognizable are the traces of the Roman walls, the forum, the baths, the theater;
- the Oasis of Guardiaregia;
- the Bridge San Rocco.