15. Gien in Sully-sur-Loire

The castle cannot be visited and is not visible from the entrance pavilion.
The entrance pavilion is the only remaining part of the 17th century castle. The main body has a main stone facade and a rear facade of stone and brick without decoration. In the middle of the latter, in a chimney stump is a clock which has often been referred to as the "Pavillon de l'Horloge" (Clock Pavilion). On the ground floor there is a brick vaulted passageway with stone arches and lunettes side penetrations. On each side of the main body, small pavilions in annexes. The whole has not been altered.
Source of information: Base Mérimée

This castle is the first of a long series that will accompany you throughout your peregrination on the banks of the Loire.
Rare are the castles which underwent as many architectural modifications as that of Sully-sur-Loire. The first traces of the castle were reported in 1102, it was then a defensive post on the left bank of the Loire.
In 1218, Philippe Auguste took advantage of a disagreement between the lord of the place and the bishop to briefly seize the place and build an imposing cylindrical tower, unfortunately disappeared. After a devastating flood in 1363, the castle changed family in the name of the marriage of the sole heiress to Guy de La Trémoïlle. The latter embarked on a major renovation project and asked the architect of the king and the Louvre, Raymond du Temple, to draw up new plans.
At that time, Joan of Arc stayed in Sully twice to visit King Charles VII, who was visiting the castle. From the 18th century, the castle of Sully-sur-Loire was the subject of many destructions and reconstructions that in turn changed its appearance.
To visit the castle of Sully-sur-Loire

Originally located in the forecourt of the castle, the collegiate church of Saint-Ythier was a seigneurial church served by the monks of Saint-Benoit-sur-Loire, to whom it was granted in 1137, then as a collegiate church in 1193. In 1608, Sully (of Protestant religion) had it dismantled and rebuilt on its present site.
The name of Saint Ythier remains attached to a miraculous navigation, because his remains were entrusted to the waves in a light boat that landed at Dampierre-en-Burly.
Inside, 16th century stained glass windows and 18th century furniture.
Place Maurice de Sully
Maurice de Sully was born around 1120 in Sully. The son of a peasant, he takes his name from the time when citizens who had no name were named after their hometown. After becoming a canon, he became bishop of Paris in 1160. He decided the construction of Notre-Dame de Paris and began work in 1163. His statue is displayed above the entrance porch of the church.