As I mentioned in another thread, when I first entered Black Forest I found a stone tower and moved into that. Turns out it was very close to a greydwarf nest and in the roaming area of a troll. I built tall walls around it and a tunnel to get in and out undetected, and stayed very quiet when I heard the troll about.

I distinctly remember coming back at one point later in the game and showing those guys who was boss!

This is what it looks like now. I don't remember why I left, but, from the looks of the place, it's likely that the troll heard me at some point and showed me the way out!

https://steamcommunity.com/sharedfiles/filedetails/?id=2976258357