Castello di Monreale, Medieval castle in Sardara, Italy

Castello di Monreale is a ruined castle on a hill at about 280 metres above sea level in Sardara. Its walls link eight square and circular towers, a combination found in no other Sardinian castle. At the centre, on the higher of two summits, stands the keep, with walls about ten metres high and two metres thick, built of mixed stone and pierced by no windows or arrow slits.

The dating of Castello di Monreale is uncertain; it may have been built between the late 9th and early 10th century, after the Sardinian giudicati arose, on earlier nuragic structures. In 1309 King James II of Aragon granted the "royal" castle to Mariano and Andreotto de Bas, judges of Arborea, and it was administered by Pisa. It peaked under Eleanor of Arborea; after the 1409 battle of Sanluri it sheltered William III of Narbonne, and it served as a district prison until the 17th century.

The name Monreale, 'royal mountain', was already attached to the castle in 1309, when James II of Aragon granted it to the judges of Arborea. Inside the walls stood a village and a small church dedicated to San Michele. After the defeat at Sanluri on 30 June 1409, the last Arborean judge, Guglielmo III of Narbona, took refuge here.

The hilltop location requires some walking and climbing to reach the ruins, so wear sturdy footwear and bring water for the journey. The high vantage point offers clear views of the surrounding landscape, making the effort worthwhile.

The curtain wall linked eight towers, both square and round, a combination found in no other Sardinian castle. The keep on the higher of the two summits, at 280 metres, still stands about ten metres high with walls two metres thick, built of mixed stone and pierced by no windows or arrow slits.