The Castrizán Fortress was built between the months of August and September of the year 1477 by the archbishop of Santiago Alonso de Fonseca II. Its aim was to guard the south access, reinforce the surroundings of Pontesampaio and act as a barrier for the Soutomaior Fortress, the main home of the conde de Camiña, Pedro Álvarez de Soutomaior.   Built with stone from monte Viso, it is a fortress perfectly adapted to its role. Firstly because of its location: it has a privileged view and dominates the communication routes and the environment. Secondly due to its morphology: it is covered with defensive systems such as a robust wall, battlements, a barrack to protect the main access… Additionally the tribute tower was not attached to the wall but placed in the centre of the enclosure. It also had two accesses and intramural structures. Remains of the old tower of the house were also found, in the middle of the enclave, under the church, occupying a prominent position.   The fortress was demolished by the conde de Caminha who, after his stay in prison in Castile, subdued Castrizán in 1478/9 with don Álvaro de Varcea, a veteran ally of the archbishop of Santiago. They defended the fortress and barricaded themselves in the tribute tower until it began to sway and they were forced to surrender.   Part of the stone was used for buildings in O Viso and Redondela and the other was reused to build the chapel of Nuestra Señora de As Neves da Peneda, already in modern times. The remains of Castrizán are still visible under the shrine