The Avignon Chart

Portolan charts are navigational maps based on compass directions and estimated distances observed by the pilots at sea and were noted for their cartographic accuracy. The so-called Avignon Chart (Carte d’Avignon) dates to around 1300, making it one of the earlier portolan charts known to exist.

Read this article about the chart (translated from the original French) that discusses its provenance and how its approximate age was determined.

Via The Map Room