The appartment is very well located. Is about 5 minutes walking to Monastirakis square, where is a metro station. But you don't need to take the metro to visit downtown Athens since Monastirakis, Plaka and Sytangma are within walking distance.
Near the appartment there are a lot of restaurants and taverns, and Kostas advice us on where to go and it was great!! Real greek food, with greek people, not tourists and fair price. Albeit there is so much life near the appartment, this is really quiet, you don't hear the noise from the street.
The appartment is very clean and very well equiped, you have everything you need. Kostas and his sister Eva also live in the same building, which is great because they are very accesible and you can contact them in case you need anything. Kostas was very very friendly, he is so nice. The appartment and the building is full of Eva's paintings which are just great and make you feel home.
They also arrange with us a taxi driver from/to the airport and to some points we had to go, and this service was great, the taxi driver is very punctual and efficient.
We had a wonderful stay here and will come back if visiting Athens again!!! Totally recommended!!!