This has probably been mentioned/reported before, but it still exists, so I’m reporting it again.
Basically, there is not 177 areas to explore in Ascalon, but 178.
As you can (hopefully) see in my screenshot “proof1”, I had 3 areas left to explore, yet the achievement said I only had 2.
I explored 2 of those places, which should have meant I only had 1 left, which in this case was: “Fields of Ruin – Last Stand Shelter”.
However, after exploring those 2 areas, the achievement completed; I scrolled down the list expecting to see “Fields of Ruin – Last Stand Shelter” still unticked in the checkbox, but it wasn’t. It was ticked as if I’d been there, even though I actually hadn’t.
See my screenshot “proof2” to understand.
proof2: http://i.imgur.com/Aof2NjX.jpg
