Chambord is the largest castle in the Loire Valley, built in the 16th century as a hunting lodge for King Francis I. It features a distinctive double helix staircase attributed to Leonardo da Vinci and over 400 rooms. The castle is surrounded by a 5,440-hectare hunting park, the largest enclosed park in Europe. The architecture blends French Gothic with Italian Renaissance elements, making it a unique architectural masterpiece and symbol of French culture. A UNESCO World Heritage Site since 1981.