Naples or Bologna?

From Bologna the sea means a train of about an hour to Rimini or Cervia. The Adriatic there is shallow and warm but often greenish, and the shore is long rows of rented sunbeds, so it works as an escape from the August heat rather than as a reason to go.

Naples is not a beach city either, but it lives on the water. You can swim off the rocks below the Lungomare or at Posillipo, and the clear, rocky coves of Procida, Ischia, Capri and the Sorrento peninsula are a boat ride away.

These are two of Italy's great food cities, and they cook very differently. Bologna is about rich egg pasta and pork: tagliatelle al ragù, tortellini in brodo and mortadella, with Parmigiano and balsamic from the towns nearby and the lanes of the Quadrilatero still working as a market.

Naples eats faster and louder. Its food is pizza in plain rooms at shared tables, fried street food, sfogliatelle and seafood pasta, built on buffalo mozzarella, lemons and San Marzano tomatoes. Neither offers much beyond its own cooking. Bologna leans towards long sit-down trattoria meals, and Naples towards eating on your feet.

Bologna's appeal is a whole medieval city in brick: the porticoes, Piazza Maggiore, the Two Towers, the Santo Stefano complex and the anatomical theatre in the Archiginnasio, all seen well in two or three days.

Naples goes deeper. Its Greek street grid is packed with Gothic and Baroque churches, the Archaeological Museum holds the frescoes and mosaics from Pompeii, the Veiled Christ lies in the Cappella Sansevero, and below it all is a second city of tunnels and catacombs. A week here still leaves things unseen.

Both cities go out late and cheaply, led by students, so the difference is in the setting. In Bologna the night moves through taverns on Via del Pratello and student bars around Piazza Verdi, with aperitivo and wine bars nearer the Quadrilatero, and the city goes very quiet in August.

Naples takes it into the open air, with crowds on the steps of Piazza Bellini and better-dressed drinkers in the alleys of Chiaia, while in summer the dancing moves out to the coast. Neither is a city for serious clubbing.

Bologna offers easy green escapes: the arcaded climb to San Luca, the Colli Bolognesi, the gypsum caves of the Parco dei Gessi, and the Apennines further south for hiking or modest skiing. North of the city it is flat farmland.

Naples has a far more dramatic setting on a volcanic bay. Vesuvius, the craters and lakes of the Phlegraean Fields and the underwater park at Gaiola are all close, and the Amalfi Coast, Capri and Ischia add walks high above the sea. What Naples lacks is green space inside the city.

Both are superb bases, for different kinds of outing. Fast trains from Bologna reach Florence in about half an hour, and with Ravenna's mosaics, Ferrara, Modena, Parma, Verona and Venice all close, it is a gateway to the art cities of the north.

From Naples the trips lead to the ancient world and the sea: Pompeii and Herculaneum on the Circumvesuviana, the palace at Caserta, ferries to Capri and Procida, and the Amalfi Coast beyond Sorrento. Bologna's trips are easier to make, and Naples's offer more varied landscape.

Neither city has much built for children, but Bologna is gentler to move around with them. The centre is flat and mostly car-free, the porticoes give shade, and older children can climb a medieval tower, with Mirabilandia and the beach at Rimini to fill the gaps.

Naples welcomes children warmly but makes the days harder, with scooters, broken pavements and steps that defeat pushchairs. It does have a zoo, Edenlandia and a science museum, plus the funiculars, ferries and Pompeii, though many families stay in Sorrento or on an island instead.

Bologna is much simpler. Its small, flat centre can be walked in shade under the arches, private cars are kept out of much of it, and the station sits at the edge of the old town, so you rarely need even the buses.

Naples has a metro and four funiculars, and the art-filled stations of Line 1 are worth seeing in their own right. Beyond them the buses crawl through traffic, the Circumvesuviana is packed and often late, and walking means sharing the lanes with scooters and crossing roads with some nerve.

Neither city is a shopping destination, and what you take home differs. From Bologna it is mostly food: mortadella, aged Parmigiano and balsamic vinegar from the Quadrilatero delis. There is also a small luxury cluster on Via Farini, and antiques fill Piazza Santo Stefano on some weekends.

Naples has more character in its crafts and cloth. It offers tailored suits and silk ties from Chiaia, nativity figures from Via San Gregorio Armeno and coral and cameos from Torre del Greco, with Via Toledo and the Galleria Umberto I for everyday browsing.

Bologna eats well for less than Italy's main tourist cities, and its churches and squares are mostly free. Rooms in the old town, though, are priced like the rest of prosperous northern Italy and become scarce during the big trade fairs.

Naples stretches money further from day to day. Pizza, street food, coffee at the bar, transport and the B&Bs in the historic centre all cost noticeably less. Spending rises mainly when you head for Capri, the Amalfi Coast or the big archaeological sites.

Each city has a historic opera house at its centre, and Naples has the grander one. Bologna's Teatro Comunale runs a full season, and the city adds basement jazz clubs, student indie gigs and summer concerts in Piazza Maggiore.

The Teatro di San Carlo, the oldest opera house in Europe still in use, is worth planning an evening in Naples around. The city adds chamber music in its churches and Neapolitan song in small venues and trattorias. Bologna has more jazz and small gigs, while Naples has the bigger single draw.

Thermal water is where these two part ways. From Bologna, the spring-fed pools of Castel San Pietro Terme and the old valley spa at Porretta Terme make a quiet half day out, and in town rest means a long lunch under the porticoes, away from the noisy university quarter.

Naples, loud as it is, sits on volcanic ground with real springs. Agnano on the edge of the city has been used since Roman times, and Ischia, an hour away by hydrofoil, is a whole spa island of terraced pools above the sea. In the city itself, the Lungomare at dusk and the cloisters of Santa Chiara are the calm corners.