Acropolis (Gr. akros, top, polis, city), literally the upper part of a town. For purposes of defence early settlers naturally chose elevated ground, frequently a hill with precipitous sides, and these early citadels became in many parts of the world the nuclei of large cities which grew up on the surrounding lower ground.
The word "Acropolis", though Greek in origin and associated primarily with Greek cities (Athens, Argos, Thebes, and Corinth with its Acrocorinth), may be applied generically to all such citadels (Rome, Jerusalem, Celtic Bratislava, many in Asia Minor, or even Castle Hill at Edinburgh).
The most famous example of the kind is the Acropolis of Athens, which, by reason of its historical associations and the famous buildings erected upon it, is generally known without qualification as simply "The Acropolis".