The apartment has a great location, is just in the heart of the city, next to Plaza Mayor, so all main attractions can be reached by foot. It is a nice, small apartment which offers you everything you need for a city trip in Madrid. There is only one thing you should be aware of: the ceiling is low so that my partner with almost 2 meters could not quite get up (only in the kitchen part).
The communication was easy and Marco was waiting for us on time, explained us everything and helped us in everyhing.