Dating from 1513, a map drawn by Turkish mariner Piri Reis is one of the earliest cartographic depictions of the Americas. Historians have long been fascinated by many aspects of his map, such as its level of accuracy. The route to the New World, the Americas, was at first a secret closely guarded by the Spanish and Portuguese navigators who were exploring the Atlantic – for example, Christopher Columbus, who was working for the Spanish monarchy. Reis surprisingly placed the New World on the correct longitudinal meridian in relation to the African continent. His was the earliest known map to do so. However, similar to other maps of the time, the scale of this map is inconsistent, with the Americas drawn much larger than Africa or Asia. Piri Reis wrote on the map itself that he had consulted other maps in Arabic, including some classical sources. He also referred to four contemporary Portuguese maps, as well as one by Columbus. The mystery remains, however, as to how Piri Reis gained access to Columbus’s discoveries.