Konstantinos place is fantastic!!! You can do everything walking and the flat is close from almost everything important in Athens. There are lots of bars, coffees and restaurants nearby. Very close from Syntagma metro station as well. The flat is very clean, has everything you need to cook, air conditioner and all the furniture are brand new.
Konstantinos since the beginning helped us a lot. Very easy going guy, easy to talk to him and very fast to give us a solution when we needed his help. Defenetly If I came to Athens again I would stay in his place.