Conwy was built by King Edward I of England in the late 13th century in Snowdonia, northern Wales.
Crac des Chevaliers was built by an elite order of Christian warrior monks in the 12th and 13th centuries.
Dover Castle was commissioned by King Henry II in the late 12th century as a mighty fortification to guard the region of Kent
Chateau Gaillard was constructed by King Richard I in the late 12th century.
Malaga was transformed into a military stronghold by Muslim leader Yusuf I and his successors in the 14th century.
Malbork Castle was forged by the Teutonic Knights, a powerful order of German crusaders, in the 13th century.