Walking through the city for one day is not enough to appreciate the beauty of the city for two reasons: first, because Napoli hides a Millenial history, made of archeology, tradition, food, and natural beauties; second, because it is a city that has to be lived in order to appreciate and know it fully.
A brief history of Napoli
It's one of the Italian and European cities with the highest population density, thanks to its history that contributed to shaping the town planning. Napoli was founded by the ancient Cumans in the VII century BC, and it became one of the most important cities of Magna Graecia for many reasons. Its position in the Mediterranean was one of them, as it is located in the Gulf of Napoli, which was the heart of the Mediterranean trade. Its culture is another reason because it is always been able to influence the surrounding populations.
In the VIII century AD, after the fall of the Roman Empire, Napoli became a duchy and declared itself independent from the Byzantine Empire. Six hundred years after, Napoli became the capital of the Reign of Napoli, and during the Restoration period, it kept its rule as the capital of the Reign of two Sicilies (Regno delle due Sicilie) until the unification of Italy.
Its extraordinary culture placed Napoli on the Olympus of universities: the University Federico II is the oldest public university in Europe, and the University L'Orientale is the biggest and oldest one for foreign languages in Europe.
This brief history is enough to understand the immense cultural, artistic and historical heritage of the city.
Things to see in Napoli
In order to visit it and see everything, you'll need 4 to 7 days. You can also stay a weekend, but it won't be enough to visit the whole city. There are so many things to visit, such as archeological sites, historical monuments, art: they all represent the legacy of the many populations that inhabited the city.
Monuments and architecture: a precious treasure of the city
One of the most famous streets is surely Spaccanapoli (literally, Naples Splitter) that, as the name might suggest, it divides the old center of the city into two parts from Quartieri Spagnoli to Forcella. You need 30 minutes to walk all of it, and you'll find yourself surrounded by many artisans' shops, pizzerias, and traditional Neapolitan restaurants.
Another famous street is Via Roma, which is the heart of shopping. At the end of Via Roma, you'll find Piazza del Plebiscito, one of the biggest squares in Europe. A bit further you'll find Maschio Angioino, the old castle and also one of the best-preserved architectures in the world, which is situated next to the National Library, which faces Piazza del Plebiscito. You'll get to the seafront very easily, you just have to go a bit further, and you'll see Castel dell'Ovo, a fortress right on the sea that is one of the oldest castles in Napoli: it dates back to the I century BC.
If you decide to go to the other part of Spaccanapoli in direction of Forcella, you'll find Piazza del Gesù and Piazza San Domenico (famous for their obelisks), and San Gregorio Armeno, where little statues for crib are made: the Neapolitan art of crib-making is famous all over the world and it's really ancient.
The parallel street to Spaccanapoli is Via dei Tribunali, which is the right street to eat pizza, as here you'll find the oldest pizzerias in the city. At the end of Via dei Tribunali there's Port'Alba (famous for its old bookshops) and Piazza Dante. Going north, you'll find the National Archeological Museum.
If you go to the neighborhood Vomero, you can visit the Certosa di San Martino, and also the third castle of the city: Castel Sant'Elmo. Here you have a wonderful panorama, a wonderful sight of the whole city.
The monuments of the city, the archeological sites, and the architecture represent a unique treasure. Two of the most beautiful churches are Santa Chiara (also famous for the old cloister decorated with majolica) and San Domenico Maggiore, in the zone of Spaccanapoli. The cathedral of Santa Maria Assunta is the Duomo of the city, which is located in Via Duomo.
Pompeii and Ercolano
Once you're in Napoli, you'll have the chance to go back in time to 2000 years ago. No, you won't find a time machine, you just have to go to Napoli Centrale (Napoli Central Station) and take a train to Scavi di Pompei ed Ercolano (archeological sites of Pompeii and Ercolano): that's the only time portal you'll need. The cities of Pompeii and Ercolano were buried by the eruption of Vesuvius in 79 BC. Those are the most important archeological sites in the world, as they show the two cities at the exact moment of the eruption, so they've been very well kept.
Gastronomy and Neapolitan food tradition
While walking through the city streets, you can get energy by eating the food of the richest cuisine in the world. The influences of many populations made Neapolitan cuisine one of the most variegated ones, with a mix of rich and poor dishes, sweet and salty ones, everything.
In Napoli, you must eat Pizza at least once. This famous food was created here, you'll find the oldest pizzerias in the world that offer the original Neapolitan pizza. You can find them mainly on Via dei Tribunali, Forcella and Spaccanapoli. While walking you can also stop and taste the delicious street food: frittata of pasta, pizzette, calzoni, mozzarella, and so on.
Among all the first courses, you have to try Spaghetti with Clams (Spaghetti e vongole), spaghetti alla puttanesca, and ragù. You have then to eat the so-called pane cafone, which is the perfect combination with mozzarella, another famous dish that originated in Napoli.
As regard as sweet dishes, you have to try sfogliatelle, nuvolette, babà, zeppole of San Giuseppe, pastiera, mostaccioli, and Caprese cake.
Every recipe has its roots in the old Neapolitan tradition.