Take the passage that runs along the mountains west from the Ruins of Rkund all the way to the troll's den. The troll has made a den out of a ruined Nordic barrow. Presently he's sharing it with a dead goat and three lootable skeletons. There's also a chest with some very nice loot and a couple urns.
A skill book can also be found simply by traveling east from the barrow down the path. The skill book is next to a fallen tree. (See: Gallery pictures)