The fastest way to get this when you're a low level is to set a random destination and walk that way.
On your compass that shows you North, East, South, and West will have little tiny triangles on the bottom of it. (Don't confuse this with the large tally marks that represent quest objectives.) If the small triangle is just an outline and not colored in, that means it is an unexplored location so walk towards it and keep an eye out for points of interest.
But if the small triangle is colored in it marks an already explored area that you may fast travel to.
Tip: The exp gained over time by exploring (Not to mention the looting and killing you will do on the way there.) Serves as a great EXP booster. So leveling should be a bit faster.
(You can also get the 'Explorer' perk at Lvl 20 which reveals all unexplored locations on the map.)