Maria's apartment is very nice, spacious, design and clean. We could stay at 6 comfortably. The flat is well located, at 2 min walk from the nearest tube station and at 10 mn of the Retiro Park. There is grocery stores, pharmacy and bakery at 2 mn walk from the flat as well. The area is safe and quiet. We only had a problem with the shower that was fixed and the clean team arrived a bit late on the first day but Maria did everything to fix it.
Would recommend this place!