I decided to work on some achievements as I level on Kaladim now (I've always ignored them for the most part). I ran around the Commonlands and got the Exploration achievement for visiting all the spots listed... then as I was finishing up some quests, I got 2 more discovery credits. I guess these were for spots that weren't on the achievement list? Is there any way to see all the discovery location spots in a zone? Or at least how many there are? I thought once you got the achievement, you had found them all, but apparently not.
