the oldest known world maps date back to ancient babylon from the 9th century bc. the best known babylonian world map, however, is the "imago mundi" of 600 bc. the map as reconstructed by eckhard unger shows babylon on the euphrates, surrounded by a circular landmass showing assyria, urartu and several cities, in turn surrounded by a "bitter river" (oceanus), with seven islands arranged around it so as to form a seven-pointed star. the accompanying text mentions seven outer regions beyond the encircling ocean. the descriptions of five of them have survived. in contrast to the "imago mundi", an earlier babylonian world map dating back to the 9th century bc depicted babylon as being further north from the center of the world, though it is not certain what that center was supposed to represent.