The stay at Eleftherios's apartment was perfect. The house is located is the middle of the city, very close to the acropolis, that you can reach on foot in less than 5 minutes.
Eleftherios was very kind during the check-in, giving me useful information about the city and its main attractions. The apartment itself is quiet, has a comfortable bed and a well-equiped bathroom.
I would definitely recommend this place to anyone who wants to visit Athens and stay in the centre of the city.