Naso's place is fantastic! It is located two blocks away from the acropolis (5 minutes walk) exactly in the middle of the city center. The place is very clean, spacious and nice and it was just perfect for me and my two friends. Nasos himself is a very kind person and picked us up from the station, gave us a lot of great tips for our travel and he was always available to reply our questions. If you are looking for the best place in Athens it is for sure Naso's apartment.