Affiches Old Mediterranean sea map

This is and old map of Mediterranean sea, also known as "Portulan" Portolan charts are navigational maps based on compass directions and estimated distances observed by the pilots at sea. They were first made in the 13th century in Italy and later in Spain. With the advent of the Age of Discovery, they were considered State secrets in Portugal and Spain. They were very valuable in the description of Atlantic and Indian coastlines for newcomer English and Dutch raiding, and later trading, ships. The word portolan comes from the Italian adjective portolano, meaning "related to ports or harbours."