Krak de Chevaliers
At the end of the 12th century, the Knights Hospitaller built another defensive wall around the central castle, whereby they closed in  of the hill. This wall was also very thick and strong. There are towers at positions along the wall. The first towers to be complete were square in shape, but the later ones were semi-circular. There were two gates with barbicans, one behind the other and joined together by a stone passage with a stone vault. Another postern gate was in the north wall, in a strong position. The Crusaders built many other buildings and made many improvements to the fortifications during this time. The castle was the Hospitallers' headquarters. The Crusaders built the castle's great hall () around 1200. The knights lived together in the great hall. Most of the buildings were complete by around 1220.