I hate to post such a trivial matter here, but I cannot, for the life of me, figure this out for myself (and Google isn't helping).
I'm trying to complete the exploration achievement on Balmorra, but, try as I might, there's a part of the Sundari Flatlands that I can't find (it's showing in the log as" 3/4 Sundari Flatlands"). I've even found that hidden (and empty) area below-right of where my marker is (wandering around in there did nothing but get me stuck in a hollow mountain).
I also found the datacron behind the Balmorra Arms Factory; it's a closed map back there, so coming at this unexplored area from that direction is a no-go.
Below is an image of the Flatlands as it appears in my map view, highlighting what I think is the only possible place I have left to explore, and showing why I can't get to it (grey line is mountains and red line is a red energy wall).
Any help on this would be appreciated, as I'm kinda OCD about this exploration.