The Paiva River is a river that rises in the Sierra de Leomil, more specifically in the parish of Pêra Velha, Aldeia de Nacomba e Ariz - belonging to the municipality of Moimenta da Beira - and flows into the Douro, in Castelo de Paiva, flowing through the parish of Fornos on the left bank. On the right bank, it flows through the parish of Souselo, Cinfães.