Ottoman admiral Piri Reis compiles a world map from older charts, including one he credits to Columbus. Its southern coastline later fuels claims of lost knowledge.
Contested history
Consensus: The Piri Reis map of 1513 is an Ottoman world map compiled from older sources, including a lost chart attributed to Columbus.
Compiled from European and Arab source chartsEstablished
Piri Reis's own marginal notes say he drew on about 20 older maps, including one by Columbus.
Its southern coast is a distorted South American coastlineEstablished
Historians of cartography read the bending southern shore as the map's limited space and the errors of its sources.
It shows Antarctica's coast before the iceDebunked
Charles Hapgood's 1966 claim requires the coast to have been ice free millions of years ago, long before any humans could map it.