An austere façade precedes the interior of tufa that gives it such durability and well-define lines. In the right arm of the transept, the tomb of François II, that cathedral's masterpiece, was sculpted by Michel Colombe in 1507 upon the request of the duke's daughter, Anne de Bretagne. The building, one of the great productions of the Renaissance, is lit by a 25-metre glass dome by Chapuis dedicated to the saints of Britanny.