The world's four great ancient capitals of civilization refer to Rome, Italy, Athens, Greece, Cairo, Egypt and Xi'an, China; there is another saying for Rome, Italy, Istanbul, Turkey, Athens, Greece and Xi'an, China. The world's four great holy cities, general refers to the human or social civilization of the occurrence of significant impact; or a country or region of civilization and culture of the collection of the great; or a religion of pilgrimage to the holy land, etc.. The world's four great holy cities, refers to Jerusalem, Mecca, Luoyang and Athens.