I highly recommend César's place. It's located on a quiet street in the heart of San Telmo. The famous flea market is right around the corner and Plaza Dorrego is just a few minutes' walk away. The house is beautiful with a lovely courtyard and colorful sitting areas. The room I rented was simple but clean and with all the necessities supplied (bedding, towel, plug adapter, etc.). The room is separated from the main house via the courtyard - it even has its own staircase - so there is a feeling of privacy. Still, Cesar is right there and always responsive should guests need anything. Breakfast was served by César and his wonderful mother with the other Airbnb guests in attendance. It was a nice way to start the morning. Thanks!