An acropolis (Ancient Greek: ἀκρόπολις, akropolis; from akros (άκρος) or akron (άκρον), "highest, topmost, outermost" and polis (πόλις), "city"; plural in English: acropoles, acropoleis or acropolises) was an ancient Greek settlement, especially a citadel, built upon an area of elevated ground—frequently a hill with precipitous sides, chosen for purposes of defense. Acropolises also had a function of a religious sanctuary with sacred springs highlighting its religious significance. Acropolises became the nuclei of large cities of classical antiquity, such as ancient Athens, and for this reason they are sometimes prominent landmarks in modern cities with ancient pasts, such as modern Athens. One well-known acropolis is the Acropolis of Athens, located on a rocky outcrop above the city of At