Northern round tower on which a windmill may have been built. Salt paper print by Louis de Clercq (1837-1901). Musée d'Orsay (PHO1986-133-2-26)

This photograph by Louis de Clercq provides a reminder of the so-called “windmill” tower built on the northernmost round tower of the second enceinte. The mill was reconstructed by Baron Rey in his bird’s eye view of the castle.