The orientation of the map by Fra Mauro (active ca. 1430-ca. 1459/1464), with the south at the top, may be its most immediately striking and intriguing characteristic to the modern observer, who may find the arrangement confusing. Because we are accustomed to reading maps with the north at the top, it can be difficult at first to make sense of the relations among the land masses. Map orientation is a convention that has undergone numerous changes over the centuries. Most world maps designed between 1150 and 1500, for example, are oriented with the east at the top, both because the sun—associated in Christian cosmology with Christ—rises in the east, and because it was believed that the Garden of Eden was located in that direction.

Still, Christian cosmology also found reason to orient maps toward the south. Eden, the Earthly Paradise, was indeed thought to be in the east, but at an unspecified location somewhere in the Southern Hemisphere, in correspondence to the Heavenly Paradise, which was held to stand at the peak of all the celestial spheres, and thus be rightly positioned at the uppermost part of cosmological diagrams. Among the world maps of Fra Mauro’s time, a Southern orientation is featured in the 1448 world map by Andreas Walsperger, in the so-called “Borgia World Map” produced during the first half of the 15th century, and in the “Zeitz World Map” from the last quarter of that century.

A Southern orientation is also common in Medieval Islamic maps, perhaps in accordance with Aristotle’s description, in De caelo, of the Antarctic Pole as the highest point in the universe. Fra Mauro provides no explanation for the south-up orientation of his map, no doubt presuming to adopt a widely shared convention of using the Sun at its peak—the most prominent astronomical element along with the Pole Star—to precisely determine the direction of the meridian passing through the Earth’s poles.