Il fiume Tammaro (78 km) nasce nel Molise non lontano dal confine con la Campania, in cui entra tra Sassinoro e Santa Croce del Sannio, in provincia di Benevento.
A river with torrential character flows for long paths located between the mountains, changing direction several times until reaching the Calore, of which it is the main tributary, close to Benevento, in Ponte Valentino, in correspondence of the railway station of Paduli. Along the way, the help of twenty-two tributaries enriches it.
