Although Winner had accepted this & related drawings in Rotterdam as being by Jan, Ruby believes that they are copies made in Rome after his (now lost) originals. Other copies inscribed with the same handwriting are now in the Ecole des Beaux Arts, Paris. Jan had probably brought with him to Rome a sketchbook of motifs that he had drawn while in Naples. He would use those motifs frequently in his paintings. The subject of this drawing, the Castel d’Ovo, appears in early works in Milan and Madrid, as well as in later paintings in Munich