portolan charts[0] were already common by the time this map was made, so coastal regions, especially in the mediterranean, were better documented. [0] https://

portolan charts[0] were already common by the time this map was made, so coastal regions, especially in the mediterranean, were better documented. [0] https://en.wikipedia.org/wiki/Portolan_chart https://en.wikipedia.org/wiki/Portolan_chart