Natalia y Roberto's apartment is in the center of the old city, so it is very convenient for walking anywhere in central Madrid. It's a 15 to 20-minute walk to many sites: the Prado, Real Jardín Botánico, El Retiro Park, Puerta del Sol, Royal Palace, the Gran Via and the barrio La Latina. Atocha Station is also very close. For walking, be aware the place is on a street with a moderate sized hill.
The apartment had all the amenities we needed or wanted--large windows, good lighting, a comfortable sofa, an espresso machine, a nice shower and lots of electrical outlets. The building is old, but the apartment is bright and up-to date, comfortable and pleasant, with artistic touches. We appreciated a list of restaurants that were described, marked and numbered on a map. Other tourist information was provided as well. The plaza right in front of the apartment has a lot of activity throughout the evening, but closing the windows subdues the sounds.
Natalia is very responsive, communicative and kind. We would definitely recommend Natalia y Roberto's place.