Volunruud is south of Dawnstar and suth east of Solitude:
Solving the Door Puzzle
To acquire the items you need you have to go though the side caves from the entrance cave. There is one on the left and right of the passage to the door that will lead you forward. In the right side cave the sword is lying in the coffin at the end of said cave. In the left side cave you will find the weapon framed above the throne on which the draugr boss sits. You can kill him fairly easily by using a bow and arrow and sneak attacking him if you don’t have very good armor and weapons. I usually tank the damage and retreat to heal with magic or potions.
Killing Kvenel the Toungue
Named enemies are always tough to kill. Kvenel the Tongue is a ghost whom you can find near the wall with the word of power. He has a few other allies with him. Be sure to kill those first and then start working on killing Kvenel. A good tactic is to dodge his attacks by walking backwards and forwards in tune with your weapon swings which often avoid a lot of the blows these types of enemies deal. Be sure to keep an eye on your health, it can sometimes drop much faster than you expect.
Full Walk Through YouTube Video