Beautiful flat and excellent host, Ximena, she was most helpful.
However, you have to go up 6 floors through steep stairs to get to the apartment, I'm not sure if it's mentioned anywhere and if it's not, I think it's rather shady not to mention it beforehand. The number on the flat is indicative of a different floor, but it's actually on the 6th (7th if you're chilean, we consider the lobby the 1st floor). If you are physically impaired in any way, I would suggest you forget about this flat.