Please answer the following question: Chateau de Saumur - The Chateau de Saumur originally built as a castle and later developed as a chateau is located in the French town of Saumur in the Maine-et-Loire departement. It was originally constructed in the 10th century by Theobald I Count of Blois as a fortified stronghold against Norman predations. It overlooks the confluence of the Loire and the Thouet. In 1026 it came into the hands of Fulk Nerra count of Anjou who bequeathed it to his Plantagenet heirs. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Building