The most important fortification in the Ribeiro. Built by the Sarmiento family — Counts of Ribadavia and Adelantados Mayores of Galicia — on a promontory overlooking the confluence of the Avia and Miño rivers. Pedro Ruiz Sarmiento received the lordship from King Enrique II in 1375 as a reward for his support during the Castilian civil war. Archaeological excavations uncovered a stone necropolis with anthropoid burials dating from the 9th to 12th centuries, demonstrating over a millennium of continuous occupation.

Rising 13 metres from a granite outcrop at 506m elevation, the Torre de Sande commands the landscape between the Arnoia and Miño valleys. First documented in 1141, when King Alfonso VII donated the Castle of Sande to the Monastery of San Salvador de Celanova. By the 14th century, the fortress passed to Paio Rodríguez de Araujo, a vassal of King Juan I of Castile. Destroyed during the Irmandiña revolt, then rebuilt.