 Krak des Chevaliers can be classified both as a spur castle , due to its site , and after the 13th @-@ century expansion a fully developed concentric castle . It was similar in size and layout to Vadum Jacob , a Crusader castle built in the late 1170s . Margat has also been cited as Krak des Chevaliers ' sister castle . The main building material at Krak des Chevaliers was limestone ; the ashlar facing is so fine that the mortar is barely noticeable . Outside the castle 's entrance was a " walled suburb " known as a burgus , no trace of which remains . To the south of the outer ward was a triangular outwork and the Crusaders may have intended to build stone walls and towers around it . It is unknown how it was defended at the time of the 1271 siege , though it has been suggested it was surrounded by a timber palisade . South of the castle the spur on which it stands is connected to the next hill , so that siege engines can approach on level ground . The inner defences are strongest at this point , with a cluster of towers connected by a thick wall . 
 Krak des Chevaliers can be classified both as a spur castle , due to its site , and after the 13th @-@ century expansion a fully developed concentric castle . It was similar in size and layout to Vadum Jacob , a Crusader castle built in the late 1170s . Margat <a href='been_done' title='1'><mark>has</mark></a> also been cited as Krak des Chevaliers <a href='null_genetive' title='2'><mark>'</mark></a>sister castle . The main building material at Krak des Chevaliers was limestone ; the ashlar facing is so fine that the mortar is barely noticeable . Outside the castle <a href='null_genetive' title='3'><mark>'s</mark></a>entrance was a " walled suburb " known as a burgus , no trace of which <a href='uninflect' title='4'><mark>remains</mark></a> . To the south of the outer ward was a triangular outwork and the Crusaders may <a href='been_done' title='5'><mark>have</mark></a> intended to build stone walls and towers around it . It is unknown how it was defended at the time of the 1271 siege , though it <a href='been_done' title='6'><mark>has</mark></a> been suggested it was surrounded by a timber palisade . South of the castle the spur on which it <a href='uninflect' title='7'><mark>stands</mark></a> is connected to the next hill , so that siege engines can approach on level ground . The inner defences <a href='drop_aux' title='8'><mark>are</mark></a>strongest at this point , with a cluster of towers connected by a thick wall . 
Krak des Chevaliers can be classified both as a spur castle , due to its site , and after da 13th @-@ century expansion a fully developed concentric castle . It was similar in size and layout to Vadum Jacob , a Crusader castle built in the late 1170s . Margat done also been cited as Krak des Chevaliers  sista castle . Tdamain building material at Krak des Chevaliers was limestone ; thdashlar facing is so fine that thedartar is barely noticeable . Outside the datle  entrance was a " walled suburb " known as a burgus , no trace of which remain . To the south of the odar ward was a triangular outwork and the Crusaders may done intended to build stone walls and towers around it . It is unknown how it was defended at the time of the 12dasiege , doe it done been suggested it was surrounded by a timber palisade . South of the castle the spur on which it stand is connected to the nxt hill , soo that siege engines can approach on level ground . The inner defences strongest at this point , wit a cluster of towers connected by a thick wall .