Ravenscar Hollow is a small cave inhabited by Hagravens in the Haafingar region.
Kill the Hagraven to obtain Ravenscar Hollow Cage Key. Then flip the lever near the Hagraven’s tent to open the secret wall. There are a few cages with dead bandits in it, and there is one cage in which a bandit is trapped inside. The caged bandit will become hostle upon releasing him. There is a chest near the last two cages and a copy of The Art of War Magic on the table near the chest.