Frederick II's tower in Enna has an octagonal bergfried with a symmetrical octagonal enceinte. The Cittadella's fortifications, including part of the medieval enceinte, are intact. The is the easternmost enceinte next to the "Ninomaru", separated by the "Tenjin-bori". Beersel Castle was rebuilt from 1357 with a circular "enceinte". A castle could have several baileys but only one enceinte. It led from the "Ninomaru" into the "Honmaru" enceinte. Of the former enceinte and corner towers only a few remains have survived. The fort's main gate is located within the enceinte. The city is surrounded by an enceinte. The "Honmaru" is the central enceinte. The ground plan of an enceinte is affected by the terrain. By 1727, the enceinte, cavaliers and gateway were complete. The is the northern enceinte next to the "Honmaru". The enceinte along Rinella Bay is made up of a tenaille trace with high walls. Each enceinte is protected by walls with turrets strategically located at each corner.