The entrance to the mine is above the poison gas (as is the top of Lovis' tower and a couple other locations). In dragon form, the Black Ring camp around the mine entrance is easily visible from the quarry tower, and is a short flight to the south east (in the direction of one of the walls coming off the tower). The door leading into the mine is in the mountainside, framed by 3 large rocks.
Yeah!! Thank you, I have been stuck for hours on what to do next, wasn't sure if I had gone wrong somewhere.
