I had a great stay at Arnaldo's place. It was very clean, with really comfortable mattress and pillows! I loved the Rainfall shower.. The location is fantastic, just next to Atocha train station, all the local buses , Retiro, Botanical garden, Reina Sofia and many more sights... There are supermarkets, bars and restaurants nearby....The apartment has very good sound insulation from outside, and I slept like a baby .. Check in was easy with clear instructions and Arnaldo was available to talk whenever I needed him , I felt very secure in the Apartment as a solo traveler.. I would stay here again next time I'm in Madrid .