Alejandro's place is in a quiet residential neighborhood not far from the city center (La Latina is almost around the corner, and Plaza Mayor is easily reachable by walking). But the thing we liked most is that there's a very nice park along Madrid's river literally just behind the house (200m by walking). The apartment itself is very cozy (a lot of wood, nicely decorated) and is also well equipped for cooking, washing clothes etc. We saw Alejandro only once in the beginning of our stay, but he was very kind and helpful and recommended us places to see in Madrid.