The word "Burh" refers to an ancient fortified town or fortification in Anglo-Saxon England. Synonyms for this word include stronghold, citadel, castle, fortress, walled town, and bastion. These words all refer to places that were fortified to protect their inhabitants from potential enemies. A stronghold was a place of strategic importance while a citadel was a fortress within a larger fortification. A castle was a large fortified building, usually with a keep, while a fortress was a larger military structure used for defense. A walled town was a town with walls built around it, and a bastion was a projecting part of a fortification designed to protect its weaker points.