The appartment is according to the description and pictures but it is worth to mention that it is built from a single (old) division, which means that the sleeping room and WC have just walls and no ceiling. It is very central, in a street without traffic, near the Royal palace, Plaza Mayor and Puerta del Sol. It is interior, thus it is not disturbed by any noise.
The only drawback was the wi-fi which was not available contrarly to the description and the comfirmation of the owner! After some insistence from my side it was provided a SIM with 1GB of mobile access but it did not worked with my equipment which was really bad since I was needing the internet for professional reasons.