He also changed the curtain wall facing cityward to a bastioned front. The top of the hill is bastioned as well and is surrounded by a parapet. It was the last major fort to be built with the bastioned trace in Malta. The French forts had a bastioned construction. The overall plan was a polygon with a bastioned tower at each corner. In addition, battles were often made irrelevant by the proliferation of advanced, bastioned fortifications. The concept of bastioned towers was developed in Spain in the late 16th century. Laparelli's original design consisted of a bastioned enceinte, with nine cavaliers and a ditch. The present bastioned fort was built atop one of these burial mounds. A distinctive feature typical of the Wignacourt towers is the corner bastioned turrets. The entire medieval town was enclosed by a bastioned pentagonal wall ("illustration, below"). It was roughly square and bastioned, surrounded by a ditch and some outer earthen defenses. Between 1841 and 1844, an immense bastioned trace, the Thiers Wall, was built around Paris.