The apartment is super clean and organized. We paid about 40 € for overnight parking. Walking to Retiro or to shopping, restaurants and night life is a snap. There was some talking we could hear in the courtyard around 2:00AM (it was Saturday night in the city ,duh) and some light construction activity close. From 4:00 AM until around 7:00 AM. We were exhausted after being out in Madrid’s happening scene after dark and were exhausted so it didn’t affect our visit whatsoever. Compared to the horns and sirens in many cities it was very peaceful.