The structure of the keep of the castle of Monreale was organised in rooms overlooking the inner courtyards, which were accessed through masonry staircases.

Only the ground floor of the fortified building currently remains, but originally it ranged over several levels, as is indicated by the presence along the perimeter walls of the holes where the wooden floors fitted.

For security reasons there are no openings on the outside walls, so all the spaces, including those of the upper floors, were lit by windows overlooking the inner courtyard. This was built over several levels due to the conformation of the ground, and here, under the surface area, some cisterns had been dug which ensured plentiful supplies of water to the inhabitants of the castle.

Five spaces have been identified against the north wall, two against the southern one and one on the south-east side, besides an area on the north-eastern side which has been identified as a tower (figs. 1-2).

Fig. 1 - Plan of the keep (transposition by M. G. Arru, from SPANU 2003, p. 58).

The alpha space is in the NW corner within the keep and is the first of the five rooms located against the North Perimeter wall. It is characterised by the presence of a curvilinear wall, perhaps a structure to store foodstuffs (fig. 3).

It was completely filled with soil mixed with various materials, and has therefore been interpreted as a "dump", i.e. a rubbish dump. Seeds, bones of small animals, fish bones, coins, bronze pins, glassy fragments, bone dice, musical instrument parts and, above all, ceramic artefacts (archaic and Valencian majolica) dated between the fourteenth and fifteenth century have been recovered from the soils which filled it.

Fig. 2 - The rooms of the keep seen from above (photo by Unicity SpA).

The kappa room is located between the alpha and iota rooms.

Here, under an early fourteenth century floor, two structures have been found: a portion of a partially underground hut, dating to the dark ages, with a fireplace and animal bones with traces of slaughter and a room used, perhaps, for processing metals.

An inscription was found in the kappa room which refers to the works carried out in the castle during the first quarter of the thirteenth century.

In the iota space (fig. 4), located between the kappa and theta rooms, the collapse of the wooden flooring of the upper floors of the keep has been detected. Beneath these layers there was a dump of various materials, covering a dirt floor surface which, in turn, stood on a floor made of trachyte slabs dated between the sixteenth and seventeenth centuries. 

Fig. 3 - Alpha space: post holes and structure for storing foodstuffs (from STASOLLA 2010, p. 46).

The theta space is situated between the iota and delta rooms. Archaeological investigations have discovered a large cooking surface here, which has allowed identifying its use as a kitchen-space over a long period of time. Access was through the second level of the central courtyard, where one of the tanks and an underground room for the storage of foodstuffs are located.

The delta space is located to the East of the theta room, next to the gamma tower and could be accessed through the epsilon room. Several fragments of glass and cork were found here, obviously related to the waste from an elegant table, including a fragment of glass with the Aragon coat of arms (XV-XVI centuries). It was used as a garbage dump inside the keep, into which the waste materials were probably thrown from the top of the East tower (gamma room).

The gamma space is a square shaped room with a stretched edge leaning against the East wall of the keep. It could not be accessed directly from the ground floor, but from the first floor of the delta room, probably via a ladder. This room has been interpreted as a defensive tower, perhaps added later in order to strengthen the fortified complex.

Epsilon space The room is located in the SE sector of the keep and could be accessed from the fourth level of the central courtyard. The wooden structure supporting a landing which allowed climbing to the upper floors was located here. The importance of the epsilon space is linked to the discovery of a portion of an underground Nuraghic hut, which proves the various phases of the site prior to the construction of the medieval castle. 

Fig. 4 - The alpha, kappa and iota rooms (photo by Unicity SpA).

Fig. 5 - Epsilon space: curved wall relating to a Nuraghic hut (photo by R. Bordicchia).