Near Riverville's temple I have a trapdoor that should lead down to the dungeons/prison but instead the trapdoor has a marker for the Broken Tower Redoubt in the Reach of Skyrim? I have the latest patch for the game, so haven't a clue as to what's going on! Also in the Shimmering Grove cave for the Wanted in Riverville quest there is a massive hole in the caves floor that the player can fall through, luckily it just drops you back by the back entrance near the exit, it's situated near where the second lat troll is in the water at the bottom of the wooden stairs.