Upon entering you will find a stare case and two lock pickable doors to the left and right with some supply's inside and in this room is a door that leads to the treasure room.
This room needs a key you get from taking out the alpha chaunurus in the den up the stare case and down the tunnel. When you enter the den you will be bombarded with poison as the chaunurus sit on the surrounding cliffs and rocks while ground forces swarm you to protect the alfa with the key and some gems.