Serra de São Mamede

Serra de São Mamede is a mountain range in Portalegre District, Portugal. This range is named after Saint Mammes. Together with the Serra de Arraiolos, the Serra de São Mamede is one of the few places in the Alentejo region where there might be snow in the winter. This mountain range separates the drainage basin of the Tagus to the north from the basin of the Guadiana to the south. The main rivers that have their sources in this range are the Sever and Nisa, flowing towards the Tagus, as well as the Caia River and its tributary, the Arronches, flowing towards the Guadiana. The town of Marvão is an ancient fortified town located on a ridge of the range. Its emblematic castle is an archetype of medieval castle-building. It dates back to the times of the Reconquista, the reconquest of the Iberian Peninsula from the Moors.