Engraving with gouache and watercolours, by Picard and Lahire. Beginning under the Ancien régime, a number of engravings popularized the image of Louis de Foix's tower. The oldest are copies of the one engraved by Mérian in Topographie Françaiseby Claude Chastillon (1641). But certain details set them apart, like this engraving with gouache and watercolours that shows the transformations that affected the doorway as of the seventeenth centuryand the 1727 lantern. Oddly, the Black Prince's tower is still depicted, even though it had disappeared long before.