Ivrea Castle was built on behalf of Amadeus VI, Count of Savoy, in 1358. Ivrea was built to signify the dominance of the House of Savoy over the region. The castle has four towers erected on a plan flank. It is located next to a cathedral and a bishop's palace. The castle is mentioned in the work of Giosuè Carducci.
The most significant changes were recorded at the end of the 18th century, when the castle was transformed into a prison, first destined to State prisoners and then also to common prisoners. With the prison function, which it maintained untile the first half of the 20th century, the structure was subject to a series of additions and adaptations that naturally divided the courtyard into two parts and defined the external spaces, closed by high perimeter walls.
The first studies of the structure, including the historical origins, date back to the endo of the 19th century, important documental sources for this were contributed by Giuseppe Giacosa and Alfredo d’Andrade.
In 1979, almost ten years after dismission, the restorations were completed that demolished the structures from the 19th and 20th century and rediscovered the antique structures in the courtyard and moat areas.
References:The Chapel of St. Martin is the only completely preserved Romanesque building in Vyšehrad and one of the oldest in Prague. In was built around 1100 in the eastern part of the fortified outer ward. Between 1100 and 1300, the Rotrunda was surrounded by a cemetery. The building survived the Hussite Wars and was used as the municipal prison of the Town of the Vyšehrad Hill.
During the Thirty Years’ War, it was used as gunpowder storage, from 1700 to 1750, it was renovated and reconsecrated. In 1784, the chapel was closed passed to the military management which kept using it as a warehouseand a cannon-amunition manufacturing facility. In 1841, it was meant to be demolished to give way to the construction of a new road through Vyšehrad. Eventually, only the original western entrance was walled up and replaced with a new one in the sountren side. The dilapidating Rotunda subsequently served as a shelter for the poor.