The world map of Ptolemy is not the most accurate representation of the world. This map only contains three continents on it, Europe, Asia, and Africa. While Europe is mapped almost entirely, big portion of Asia is lacking, and only the northern half of Africa is incorporated into this map. The reason for this is that the knowledge of the world at that time was very limited, so Ptolemy mapped only the places that were known until then. It has to be noted though that the map is relatively accurate when it comes to shapes and distances of the places that are mapped, so it is quite an achievement for the period in which it was made.
