We (a couple) arrived in bilbao by bus from san sebastian. A short walk to the train station and only 4 stops to Santiago's apartment. When we arrived in the old quarter it was party central as there was a massive fesitval underway. We were in the thick of all the action, however once upstairs in the apartment it was easy to get away from the noise. We had big packs but found the stairs up ok but some may struggle. We only stayed one night and spent much of our time out but it was lovely to have the apartment to easily walk home to. The next day we walked a few hundred metres to the tram that took us direct to the guggenheim, we were going to walk the couple of kms but the tram was so close and easy! (Just remember to get a ticket before boarding!) A great location to sites, food, bars, transportation. Would def recommend!