The world map by Fra Mauro (active ca. 1430-ca. 1459/1464) is splendidly painted and decorated with gold and blue, the latter pigment obtained by grinding rare lapis lazuli. It was executed on four parchment sheets assembled together and glued onto wooden panels reinforced on the back by three battens. It features neither a scale of distances nor directional lines nor rhumb lines, and indicates neither the equator nor the tropics. The only directional elements are eight wind roses located along the outer circumference of the map, which correspond to the main winds. The work appears to have been created without recourse to any cartographic projection, while it is probable that the wind roses demonstrate the traditional geometric construction used in nautical charts.
The map is circumscribed within a circular gilt frame 196 centimeters (77 inches) in diameter, in turn centered within a gilt wooden frame 223 centimeters (87.7 inches) on each side. The two frames mark out two distinct spaces. Within the circle we find ecumenical space, the discoverable and inhabitable parts of the Earth, which are described in hundreds of drawings, place names, and textual captions. Outside the circle, in the four corners of the square frame, cosmographic space is revealed. The measurements and fundamental properties of the celestial and sublunar world are described in seven long cartouches, three cosmographic diagrams, and an image of the Garden of Eden. The compositional device of a large wheel inscribed within a square, with four smaller circles in the corners, recalls classical decorative motifs: the same arrangement can be found in illuminated manuscripts, woodcuts, and paintings representing the liberal arts, the vices and virtues, the seven deadly sins, the months, and the seven days of Creation.