An alternative approach to this achievement is to level up to level 20 (but save first if you don't really want this perk). Upon reaching level 20, you may choose the explorer perk, which allows you to see every location in the game.
From there, just travel to them one by one until the achievement pops.
The way I did it was slightly less effective but it just involved fast travelling to locations that didn't have many other locations around it, and travelling off in an empty direction until a hollowed out arrow appeared on my mini map.