The Castle of Nargó, which was first documented in 1065, had various owners over its long history. It was located on what was then known as the Roca Roja (red rock), where it looked out over the road that followed the River Segre valley. Although initially a count’s castle, well into the 13th century, it ended up subject to the jurisdiction of the viscounts of Castellbò, and marking the southern limits of the viscounty. In 1513, Queen Catherine of Navarre, who was a descendant of the viscounts of Castellbò and lady of the viscounty, was at war with King Ferran the Catholic. During that war, which was won by the Spanish monarch, his troops invaded the domains of Queen Catherine and demolished her main castles. These included that of Castellbò, which was the one with the greatest symbolic value, and also all the castles that marked the frontiers of the viscounty, particularly in the Vall Ferrera and at Coll de Nargó.