Krak des Chevaliers is a medieval castle in Syria and one of the most important preserved medieval castles in the world. The site was first inhabited in the 11th century by Kurdish troops garrisoned there by the Mirdasids. In 1142 it was given by Raymond II, Count of Tripoli, to the order of the Knights Hospitaller. It remained occupied by them until it was reconquered by the Muslims in 1271.
The Hospitallers began rebuilding the castle in the 1140s and were finished by 1170 when an earthquake damaged the castle. The order controlled castles along the border of the County of Tripoli, a state founded after the First Crusade. Krak des Chevaliers was among the most important and acted as a center of administration as well as a military base.
Wikipedia https://en.wikipedia.org/wiki/Krak_des_Chevaliers
Address Syria
Coordinates 34°45'25.005" N 36°17'41.179" E