We really enjoyed our stay in Antonella’s apartment. It is furnished with style and very clean (it almost felt like we were the first guests in this apartment). The rooms are on three different floors, so you should not be too averse to stairclimbing. The rooftop terrace is very nice.
The apartment is perfectly located to visit all the main spots in the surrounding (Grotto, Alberobello, the sea cities, ...). In Castellana Grotto, it is located at the main square which has many advantages (you can easily walk to all the restaurants, ...) but of course, people meet on this square in the evenings, too.
Antonella respectively Giuseppe were very caring and also provided us with suggestions for restaurants and things to visit.