Columbia subject headings:
Harvard subject headings:
Architecture, Medieval--Syria--Qalʻat al-Ḥiṣn.
Castles--Syria--Qalʻat al-Ḥiṣn.
Fortification--Syria--Qalʻat al-Ḥiṣn.
Krak des Chevaliers (Qalʻat al-Ḥiṣn, Syria)
Qalʻat al-Ḥiṣn (Syria)--Antiquities.
Qalʻat al-Ḥiṣn (Syria)--Buildings, structures, etc.
Syria--Antiquities.
Princeton subject headings:
Castles--Syria.
Crusades.
Military architecture--Syria.
Qīr Mōav (Jordan)
Syria--History--750-1260.