Celesta's flat is in a wonderful olden-style building with a lot of charm. We stayed 3 of us but it could comfortably fit another person.
The location is convenient, equidistant between Cavour and Museo Metro stations and 15 mins from the airport. Central town is approx. 20-25 mins away. It is very convenient for Piazza Bellini, which is a vibrant night time hangout. Highly recommend the bakery nearby (turn left approx. 3 mins walk) which turns out to be one of the highest rated ones in Napoli!
We had a great stay in Naples.