Castillo de Doña Blanca is a tower built in the 15th or 16th century to watch the Cádiz bay. It is named after lady Blanca de Borbón, who was imprisoned there.
The tower is built to the archaeological area. The remains of walls, necrópolis and parts of houses date from the eighth to the third century BC and were built by the Phoenicians. It is considered an ancient city with a significant development and urban planning, which shows the great power of this port city. The first traces of occupation in the mountains and around date back to the Copper Age.
The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.