If your trip to Naples is all locked in but your travel itinerary is a bit on the empty side, let us give you a helping hand.Experience the best of what this place has to offer by adding Catacombe di San Gennaro and Naples National Archaeological Museum to your itinerary. If you've got some spare time, have a look at Castel Sant'Elmo and Naples Cathedral too.Near the city center, Spaccanapoli is one sight you might like to put on your to-do list. Naples Underground and Piazza Bellini are also close by and worth checking out.