Mar's appartment is in a quiet street of Madrid, and in the center of the city at the same time. It is near everything: museums (Prado, Thyssen...), festive streets with trendy bars and restaurants, shops, great places (Plaza Mayor, Palacio Real de Madrid...) etc. You can visit every interesting Madrid places by walking!
Finally, the appartment itself is perfect: very spacious, clean and fully equipped. I recommend it!