The apartment is right in the city center, next to Plaza del Reina. There are many tourist objectives within walking distance. We met with the husband of Javi's housekeeper who showed us where the garage is located (~3 min walking from the apartment).
the apartment is very big, and very clean. the heating is done via a Gas stove located in the living room. in the night it can be a bit cold and it's not really safe to sleep with this stove turned on. air conditioning is also available for the summer times.
Although on the english description it says that the parking is free, when we reached the apartment we were asked to pay 20 eur for the parking (2 nights). we declined and opted for finding another parking place by ourselves.
Javi later changed his mind and called us to offer the garage remote free of charge claiming that in the spanish description it is clearly written that the parking costs extra.