I stayed with Mercedes for six weeks and absolutely loved it! Her apartment is gorgeous, sunny and very clean, and I felt right at home there. The location is ideal: close to el Retiro park, Atocha station, and bus lines. It's very convenient to get to the city center, either by public transit or on foot if you're not in a hurry, but the apartment is in a calm neighborhood so you can also get a good night's sleep! Mercedes is a kind and welcoming host, and I enjoyed our many evening chats. She and her partner Juan Carlos are very knowledgeable and are available to answer any questions. 100% recommended!