Although it lines up with a couple towers, there is no tower on the inaccessable area CURRENTLY.
Also, there's an area in the NW corner of the map, in the lava, that's inaccessable as well. And that area, as it looks like on the map, has a bridge inside it, so it's meant to be accessable at some point.
There's the area to the south of the main city. On the map in this thread, you can see a building with red in it. Nearby is an inactive Moonglw-style teleporter. Or at least I don't know how to activate it.
In the north part of the map, next to the water, is a small area accessable only to flying gargoyles (and probably recalls). Nothing there but some ruined tents though.
Plenty of areas that MIGHT mean something at some point. We don't know yet though.
