Just came across this wonderful article on 13th century map-making and navigation. The mystery of how highly accurate navigational maps were created in the medieval period has recently been solved by advanced computation and mathematics. But I'm sure that in your saga, there would be a more esoteric solution involving competing attempts by Tremere naval forces, Mercere mariners, and Jerbiton merchants to create the most accurate maps in mythic Europe.
Different magi would make different maps for differing needs. A highly accurate map could be produced by magi with some simple compass-point finding and other surveying Intelligo spells. No magnetic north here; magi mean North.
Redcaps could use road maps; mariners coastal and hazard charts; merchants might organized trade routes on maps with market notes; Tremere probably has military maps with defensive points and travel times; one of Harco's best guarded documents could be a simple transit map of all their functioning and former portals.
Verditius might have maps that update themselves as they travel routes. An Auram mage might have a map of the winds over Europe. Terram magi could have maps of geologic features with little heed of rivers or seas. Seeker maps don't need to be representative of geography, just the relevant sites.
Portolano maps are very cool, though.
Back in the 3rd edition, when you could make magic items that could gain abilities, one of my players made a map and had it trained in Area Lore, for the area.
The rest of the enchantements were simply Imaginem spells to display what it new, in whatever scale was desired.