Ana's place was perfectly located at the top of the old town, 5 minutes walking. If you are afraid of stairs, there is an elevator 50 meters away that will bring you right into/outside the metro station.
JJ did a great job welcoming us in a beautiful brand new flat. Everything was clean and exactly like on the pictures. Communicating with JJ was very easy. I definitely recommend this appartment and won't hesitate to come back here for another trip in Bilbao.