The Girifalco Fortress is also called Medici Fortress because in 1561 was restored and modified by Grand Duke Cosimo I de 'Medici.
This impressive and charming trapezoidal structure is bounded by walls with four corner bastions different in shape and size.
Inside the walls there is a large garden, the courtyard and the Captain's Palace, each one having fascinating and of great interest features.
The guardhouse is of a square design laid out on two levels. The lower level, which is the main entrance to the fortress, features a low, vaulted, pavilion ceiling with lunettes and capitals of dressed stone. In the entrance wall you can still see the openings where the drawbridge mechanisms were lodged. On either side of the entrance are two sentry bunkers, strategically positioned for crossfire when under attack.
Access to the upper floor was originally via a secret staircase, which still exists, while direct access to the keep is via a staircase that was restored in 1969. The upper level of the gatehouse, currently accessible from the external ramp, is partially collapsed and roofless.
The keep is the oldest part of the fortress, and the facade which faces the courtyard is probably the only remaining trace of the original mediaeval construction. According to historical records, in 1527 the fortress was connected to the town perimeter wall via two stretches of walling which made the pentagonal shape of the courtyard. An adequate supply of water was provided by an underground storage tank located in the centre of the keep. The patrol path battlements are still accessible from the top floor of the keep, which affords a superb, panoramic view of the Chiana valley below. After the construction of the bastions in 1556, the keep became the barracks for the soldiers and the constable. You can still see traces of the roofing which once covered the barracks in the masonry of the courtyard walls, which were completed in 1624.
The roof was demolished in 1776 due to serious damage caused by rainwater infiltration.
Facing north-west towards the church of the same name, the wedge-shaped bastion of Santa Maria Nuova features one side at right angles to the town perimeter wall and one flush with it. When construction work started in 1556 to improve the fortress defense system, part of the town wall was dismantled and rebuilt to incorporate the new bastion. Inside the bastion, near the entrance, you can still see a 2-metre thick stretch of the old town walls. The restoration of this bastion was completed in 2010 with the installation of an external service elevator, which was part of a general research and re-development project for the fortress, undertaken jointly by the Comune of Cortona, the Soprintendenza of Arezzo, the Florence University architectural faculty and the Monte dei Paschi di Siena Foundation.
The bastion of Santa Margherita, facing south-west towards the sanctuary of the same name, is part of the 16th century reconstruction project that included the bastion of Santa Maria Nuova. Featuring a pentagonal design with vertical sides, it is the only one of the four bastions without a roof. However, some fragments remain that suggest it originally included some vaulted chambers that were never completed or have subsequently collapsed. On the side facing the town it is still possible to access the arrow slit which controlled entry to the fortress. The stepped ramp above was probably designed to give continuity to the patrol path battlements connecting the upper levels of the four bastions. Nowadays, the tip of the Santa Margherita bastion is an excellent vantage point for viewing the Chiana valley and Lake Trasimeno.
Looking north-east towards Mount Sant’Egidio, the bastion of the same name is shaped in profile like an ‘ox-tongue’ spearhead with two symmetrically curved sides. It has a single inner chamber of hexagonal design which could house two gunners for shooting at ground level. It was built at the same time as the bastion of San Giusto whose upper levels were connected via a rampart, still visible. A ‘Ravelin’ was built outside the bastion. This is a triangular shaped, earthworks embankment with walled sides to improve the defense system by deviating any perpendicular fire from an attacking army, thereby reducing the intensity of the onslaught. An emergency exit door, now walled in, allowed defenders to flee from the bastion towards the ravelin.
The bastion of San Giusto is positioned just outside the perimeter of the town walls in order to defend the fortress from attackers coming from the south-east. It is noted for its asymmetrical design, having one side shaped like a lance and the other side straight, which then dovetails directly into the pre-existing town walls. The interior has a vaulted main room punctuated with arches and buttresses that encompass smaller, vaulted chambers. Outside, near the entrance to the bastion, you can still see an interruption in the town wall masonry where it was partially demolished in order to incorporate the new 16th century network of bastions. At the top, on the external corner of the courtyard walls, you can see where the new blocks of stone were dovetailed into the old masonry, while at the base is an embankment which was added to reinforce the reconstructed perimeter wall.