The Vinland map is claimed to be a 15th-century mappa mundi with unique information about Norse exploration of America. It is very well known because of the publicity campaign which accompanied its revelation to the public as a "genuine" pre-Columbian map in 1965. In addition to showing Africa, Asia and Europe, the map depicts a landmass south-west of Greenland in the Atlantic labelled as Vinland (Vinlanda Insula).
The map describes this region as having been visited by Europeans in the 11th century. Although it was presented to the world in 1965 with an accompanying scholarly book written by British Museum and Yale University librarians, historians of geography and medieval document specialists began to suspect that it might be a fake as soon as photographs of it became available, and chemical analyses have identified one of the major ink ingredients as a 20th-century artificial pigment. Individual pieces of evidence continue to be challenged, most recently at a 2009 conference.
The Vinland map first came to light in 1957 (three years before the discovery of the Norse site at L'Anse aux Meadows in 1960), bound in a slim volume with a short medieval text called the Hystoria Tartarorum (usually called in English the Tartar Relation), and was unsuccessfully offered to the British Museum by London book dealer Irving Davis on behalf of a Spanish-Italian dealer named Enzo Ferrajoli de Ry. Shortly afterwards, Ferrajoli sold the volume, for $3,500, to American dealer Laurence C. Witten II, who offered it to his alma mater, Yale University.
In June 2013, it was reported in the British press that a Scottish researcher, John Paul Floyd, had identified both the source of the "Speculum" manuscript and the particular reproduction of the Andrea Bianco map which had been used to create the Vinland Map forgery. Mr Floyd had found published references in two pre-1957 Spanish books, describing in detail a 15th-century manuscript volume, clearly identifiable as the Yale "Speculum" / "Tartar Relation" book but containing no reported map. He had also spotted details in the Vinland Map which matched badly with the original 1436 Bianco map, but much better with an engraving based on the Bianco map and printed in 1782
More information, including the various analyses in the 20th and 21st centuries, on the Wikipedia page [1]
The WebExhibits page is [2]
An essay on the Map can be found here [3]
A website is [4]