Acropolis (Gr. akros, akron, edge, extremity + polis, city, pl. acropoleis) literally means city on the edge (or extremity). In Greek, Acropolis means \"Highest City\". For purposes of defense, early settlers naturally chose elevated ground, frequently a hill with precipitous sides. In many parts of the world, these early citadels became the nuclei of large cities, which grew up on the surrounding lower ground, such as modern Rome.

The word Acropolis, although Greek in origin and associated primarily with the Greek cities Athens, Argos, Thebes, and Corinth (with its Acrocorinth), may be applied generically to all such citadels, including Rome, Jerusalem, CelticBratislava, many in Asia Minor, or even Castle Rock in Edinburgh.