Great location and very friendly hosts, I really loved my time in this cute little flat. It is a 10 minute walk from Atocha and a 5 minute walk to Palos de la frontera metro, from there it is 10 minutes to the centre of Madrid.
The flat is in a grand old building in the basement and is small but there is everything you need. I was alone for most of my stay but it is more than adequate for a couple or 4 friends.
We were met at the front door by Juan who spoke good English and showed us around the flat and recommended local places for us. There are a few nice restaurants in the area, we particularly liked Bodegas Rosell just up the road and AS Fontes also (where, if you order a beer, you get a free tapas).
Would go back next time we visit Madrid, thanks for a lovely stay Laura.