The Weimar map is an anonymous 15th-century Italian portolan chart, held by the Grand Ducal Library of Weimar. Although frequently dated as 1424, most historians believe it was probably composed a half century later. The author is unknown, although said to be a member of the family of cartographers of Ancona, most probably . Faint and fragile, the Weimar map is rarely photographed and has been hard to decipher.