The apartment was very nice, clean and well equipped for a nice stay. It is located very close to the old town of Bilbao, which makes it easy to get to the center by foot. Though the apartment is very close to the center, it is quite at the same time. Basically, you here no noise from outside, even if the windows are open.
Carlos is a very nice and helpful host, which welcomes you warmly in the apartment. The folder he prepared for his guest with information about the city, excursions, restaurants, etc. is very helpful and even improves your stay. We would recommend the stay at any time :)