As others have mentioned, Maria's place is clean, walkable to major sites, and close to public transportation. Best of all, there is a good bakery opposite the apartment. Danilo, her neighbor, was very helpful. He arranged for transportation, and answered all our questions. We had a good visit. Thank you.
A note of caution about using public transportation in Athens. There are gangs of pickpockets. They surround you, while one of them tries to steal.