Martin's place is very nice, tidy and has everything you need and more! The courtyard is a nice added bonus. He's always available for questions, gives a lot of recommendations and provides you with free train tickets, should you need them. The apartment is located in a very vibrant neighbourhood, and is close to shops, metro and train stations but most things are within walking distance as well. Overall we had a very nice stay in Martin's apartment and we would definitely recommend staying here if you're in Madrid!