- Castle of the Dukes of Brittany

The original building, built by Francis II, has disappeared.

In 1670, fire swept through one wing of the building. Its reconstruction during the reign of Louis XIV brought profound transformation, with the work reflecting the Classical style of the period. In 1800, the explosion in the Spaniards' Tower (Tour des Espagnols) caused further damage. In the early 20th century the "stylistic restoration" by the chief architects at the Historical Monuments authority favoured a return to the 15th and 16th centuries, based on an idealised vision of the original form.

Pascal Prunet sees the building as doubly marked by history: first by the accidents which changed it and then by the alterations which followed, reflecting the functional constraints and the tastes of the corresponding period.

The current restoration has opted for relative balance, based on 17th century historical and architectural values. The Classical façade has been restored, but its Gothic base has been preserved, as have the restorations designed by the 19th century architects. The façade now looks as it did after the works ordered by Louis XIV in 1681: a main door covered by a canopy with a cartouche with the arms of the French royal family on the cornice above.

The Classical dormer windows, ornamented with "large trophies with shields", which replaced the Gothic dormer windows of the late 15th century, have been retained. The carved military trophies, undocumented, have not been remade. However, on the bays near the Golden Crown Tower (Tour de la Couronne d'Or), the neo-Gothic dormer windows from the 1877 and 1907 restorations have been retained.