The castle sits on the Serravalle hill, which rises above the Temo Valley and the town of Bosa. Its prevalent position in the area provided control over the river and its access from the sea as well as protecting the nearby town and its properties.
The original building dates to the middle of the XIII century, built on the wishes of the Malaspina family from Tuscany.
Even though the fortified building still maintains the original structures from the thirteenth century, a number of alterations were made by the different owners. Indeed in 1317, the castle passed into the hands of the judges of Arborea, likewise obliged to surrender it to the Aragonese domination at the end of the fifteenth century.
The defence walls from the Malaspina structures have been preserved with its towers and walkway and 20-metre-tall narrow fortified tower. Furthermore, the remains of the fortified royal residence and the palatine chapel, created between the XIV and the XV centuries have been preserved.
In the nineteenth century, the palatine chapel acquired the title of Nostra Signora de sos Regnos Altos. Even though it is small with a basic design and no significant architectural features, internally, it preserves an important decorative cycle dating from the XIV century. The frescoes represent the procession of the saints, some scenes from the life of Christ, and the unusual depiction of the meeting of the three dead and the three living, unique in Sardinia.
