Location north-west of Lorewitch

[lateralus]

Immediately north-west of Lorewitch tower is an construction situated at the very corner of the map section. I can't figure out what it is and am going to leave this area soon for the end-game. Any idea what this is? If it is a plot-point I'd rather not know, but it doesn't look like one.

[lateralus]

I just noticed this thread, which is about the same place (of course I noticed it immediately _after_ posting...

viewtopic.php?f=12&t=3794