In the 9th century, the rise of the cult of the Apostle James in Santiago de Compostela gave Galicia a particular symbolic importance among Christians, an importance it would hold throughout the Reconquista. As the Middle Ages went on, Santiago became a major pilgrim destination and the Way of Saint James (Camiño de Santiago) a major pilgrim road, a route for the propagation of Romanesque art and the words and music of the troubadors. During the 10th and 11th centuries, a period during which Galician nobility become related to the royal family, Galicia was at times headed by its own native kings, while Vikings (locally known as Leodemanes or Lordomanes) occasionally raided the coasts. The Towers of Catoira (Pontevedra) were built as a system of fortifications to prevent and stop the Viking raids on Santiago de Compostela.
To stop the Vikings from raiding, what did the Galicians build as a defense system?
Towers of Catoira