The quest begins in Selbina when you speak with the mayor, Abelard (G-9). He asks you to go around the world gathering imprints from stone monuments using a lump of clay he will give you. You must go out to a monument, trade the clay to it, and bring it back to the mayor. There are 17 monuments around the world, but only 15 are required to get the map. The two not required are in Battalia Downs and Sauromugue Champaign as they will only yield gil rewards and not count towards the 15 for the map. Coincidentally, they are also the monuments that you cannot solo because you must go through the switch gates in Eldieme Necropolis and banishing gates in Garlaige Citadel for the respective areas. All the stone monuments are marked on the maps on this site.
List of stone monuments(You can do these in any order):