For years, Napoli's pre-season training camps and in-season training sessions have been hosted at athletic facilities in Castel Volturno. It's become a tradition, something expected and comfortable... and it might soon be in the past.
Napoli are apparently looking in to using a newer and more modern facility based in Sant'Antimo, just north of Naples and much closer and easier to access from the city than Castel Volturno. Rafa Benitez apparently visited the facility recently, and was quite impressed with what he saw.
Sant'Antimo features several fields of various sizes, useful for breaking the squad down in to group to work on specific focuses, as well as a large weightroom and even some rather nice-looking pools. There's good treatment facilities on-site for those who aren't at 100%, and even what Tuttonapoli refers to as restaurant-quality dining on site, which is pretty nifty.
Of course, it's not in quite as nice an area as Castel Volturno, in large part because it's not right on the ocean*. But everything else seems like a pretty marked upgrade from what Napoli have now, so moving to Sant'Antimo seems like the smart play, even if nostalgia would want some to keep things as they are. Better facilities would, in theory, allow Napoli to do a better quality of work in training. Better training means better performance on the pitch, and doing anything to improve the quality on the pitch is a good move.
*I like the ocean, so sue me.