Antwerp was developed as a fortified city, but very little remains of the 10th century enceinte. Only some remains of the first city wall can be seen near the Vleeshuis museum at the corner of Bloedberg and Burchtgracht, and a replica of a burg (castle) named Steen has been partly rebuilt near the Scheldt-quais during the 19th century. Parts of the canals that protected the city between the 12th and 16th century have been covered and used as a sewage system. Both the 16th century city walls and the 19th century fortifications have been covered up by major infrastructure works during the 19th and 20th century.