Montsoreau Chateau

Apparently the river has shifted over the years. From Wikipedia: "The Château de Montsoreau is a castle in the market town of Montsoreau, in the Maine-et-Loire département of France. It was constructed in 1455 by Jean de Chambes, a senior councillor to King Charles VII. Erected on the bank of the Loire river, it was a strategic fortress, controlling river traffic between Chinon and Saumur. In fact the castle of Montsoreau has an exceptional position at the confluence of two rivers, the Loire and the Vienne, and at the meeting point of three historic regions: Anjou, Poitou and Touraine. Unlike other castles by the Loire, Montsoreau was directly built in the river."