The Castle-Museum of Dieppe bears witness to the medieval period of the city. Its construction in sandstone, flint, and red and white bricks spanned almost three centuries, from the 15th to the 18th century. Listed as a Historical Monument since 1904, it almost disappeared but finally became the Maritime Museum in 1923. Marine charts, navigation instruments, cutlasses, chests, and models of sailboats attest to the naval vocation of Dieppe.