Delia Castle, locally known as Castello di Delia or Il Castellaccio, lies west of the town of the same name, in the Caltanissetta province on the island of Sicily in Italy.
Delia Castle was probably built by the Normans in the 11th century, using a site already fortified by the Arabs. It was situated on a strategic location; high above the valley, on a ridge of jagged limestone cliffs, controlling the road connecting the cities of Catania and Agrigento.
The castle is said to have played an important role during the War of the Sicilian Vespers at the end of the 13th century.
In 1469, when the Aragonese ruled Sicily, Delia castle was modified and enlarged.
The nearby town of Delia was only founded in 1622 by Don Gaspar Lucchese after obtaining a permission to build and populate from Philip II, King of Spain.
When Delia Castle fell into disuse I do not know.
The narrow limestone ridge on which the castle is built forms the natural base of the walls. Several small natural and manmade caves inside the ridge, were used as cisterns and for storage.
At present Delia Castle is freely accessible. This is a very nice castle, especially for its caves.