How was the first world map drawn?

The first world map was chiseled on a clay tablet in ancient Babylon in 6 BC. The Greeks in 4 BC had similar maps though they correctly believed that the earth was not flat, but a sphere. The first reasonably accurate world map was drawn by hand on paper by Gerardus Mercator, a Flemish geographer. His first world map was produced in 1538 and improved upon in 1585.