Issogne Castle is most noteworthy for its fountain in the form of pomegranate tree and its highly decorated portico, a rare example of medieval Alpine painting, with its frescoed cycle of scenes of daily life from the late Middle Ages.
Tensions between the Bishop of Aosta and the De Verrecio family, lords of the nearby town of Verrès, reached boiling point around 1333, when the castle of Issogne, the episcopal seat, was attacked and damaged by fire.
Ibleto transformed the episcopal stronghold into an elegant princely residence in Gothic style, with a series of towers and buildings enclosed by an encircling wall.
George had new wings erected to connect the already existing buildings, unifying the complex into a single horseshoe shape surrounding a central courtyard.
The Castle hosted many illustrious guests, including the future emperor Sigismund of Luxemburg as he returned to Germany in 1414, and King Charles VIII of France in 1494.
From the exterior, the Castle looks like a fortified residence of fairly unprepossessing appearance, without any particular decoration, with angular turrets a little higher than the rest of the building.
The Castle was built to a quadrangular plan, three sides of which are occupied by the building and the fourth, oriented towards the south, comprises an Italian Garden, enclosed within a surrounding wall.
From the octagonal stone bowl of the fountain emerges a pomegranate tree made of wrought iron from which jets of water are sprayed.
It appears that the tree is to be read symbolically as the expression of the desire to unite the fertility and unity of the family represented by the pomegranate, with its seed-filled fruit, with the strength and antiquity signified by the oak.
The lunettes of the portico are decorated with frescoes giving realistic and humorous depictions of scenes daily life and the trades of the period.
The entire cycle has been attributed to an artist known as 'maître Colin' due to a graffito in the 'lunette of the guard house' that identifies 'Magister Collinus' as the author of the work.
A door in the portico leads to the dining room, roofed by a vault and furnished with nineteenth-century furniture that Vittorio Avondo had made on the basis of Renaissance models.
On the northern side, next to the staircase that leads to the second floor, one finds the so-called 'hall of justice' or 'lower halls', the principal presentation space of the Castle.
It is a large hall on a rectangular plan, with the walls completely covered in a fresco of a fictive loggia with columns of marble, alabaster and transparent crystal.
The frescoes of this hall, probably completed before the death of George of Challant in 1509, have been attributed to the Master of Wuillerine, an artist thought to have been of the Franco-Flemish school, as may be deduced from the presence in the landscapes of houses with sharply-pitched roofs and windmills of the type typical in northern Europe.
Placed along the walls on the long sides of the hall are placed carved wooden stalls, nineteenth-century recreations of the late-Gothic originals conserved in the Turin City Museum of Ancient Art.
The rear wall of the hall is pierced by a large stone fireplace decorated by a griffin and a lion that hold the arms of the Challant family aloft.
Overlapping vertically in a series of steps, these cylindrical elements form a central column that give the staircase a significant static strength.
The ceiling of the ramp is created by leaving the lower surface of the upper steps exposed, thus giving the appearance of a continuous ribbon that draws one on as one ascends the staircase.
The furnishings of the room include a large stone fireplace and a canopied bed, a nineteenth-century copy of an original to be found in the Ussel Castle.
Next to the bedchamber can be found the private oratory of Marguerite de la Chambre, a small square room covered by a cross vault.
Next to Marguerite's room, and accessible either through it or by means of the staircase, is the large rectangular hall covered with a wooden ceiling called the 'chambre de Savoie' (the Savoy Chamber) in the inventory compiled at the death of Renato di Challant in 1565.
At the back of this hall there is a large stone fireplace upon which are depicted the arms of the Savoy family, after which the room was originally named, and the united arms of the Challand and La Palud families, brought together by virtue of the wedding of Amadeus of Challant-Varey and Anne de La Palud, parents of the Prior George of Challant.
The frescoes, the work of the same anonymous Northern artist who decorated Marguerite's chapel, show the scene of the crucifixion, a pietà, and the entombment of Christ.
It is furnished with a sixteenth-century bed of Tyrolese origin, reconstructed furniture commissioned by Avondo in the nineteenth century and a stone fireplace decorated with the arms of George of Challant.
The graffiti are mostly in French or Latin, and amongst them one finds visitors' reflections on how sad or happy they are to be leaving the Castle, a great number about life or money, confessions of being in love, and mocking jibes.