Andor's Trail

I've gone through the mine, to the caves, battled everything and got to the chamber deep underground where there are three pillars with dragons on them. Amongst the pillars are two winged things I quickly dispatched.

But that's it, end of adventure. Quest incomplete.

I've been battling monsters in the mine ever since, looking for some hidden rooms or passages. But none are found.

Is this a bug?

No bug. You simply have not reached the end of the dungeon.

Is there a map of charwood mine?

I didn't find a map either and created my own