Bielka welcomed us in Carlos apartment and has been very nice and helpful. The apartment is very nice and well organized, and it's in a nice zone od Madrid with the metro and bus station few meters away.
There is a lot of shops and services and it's a great place to start visiting the city. It's easy to reach from the Airport both with trains and metro. The Delicias train station, the railroad museum and the "Matadero" are very near and especially the last one is very nice for relax a few hours.
I really liked it! Absolutely recommended for singles or couples and even for work travels.