Catania or Siena?

This is the widest gap between the two. Catania sits right on the sea. The sand of La Playa lies to the south, and to the north are the lava platforms and ladders of Aci Castello and Aci Trezza, where the water around the sea stacks is very clear.

Siena has no beach at all. The Maremma coast near Castiglione della Pescaia is well over an hour away by car, so a swim takes a whole day, and in town swimming means the pool at your hotel or agriturismo.

Both cities eat well, but Catania's food is more varied and more exciting. Its great strength is street food: ragù-filled arancini, fried crispelle, the horse-meat grills of Via Plebiscito and granita with brioche at breakfast. La Pescheria supplies the fish trattorias around the cathedral.

Siena's cooking is narrower and rooted in Tuscan tradition: pici, ribollita, cinta senese pork, and its panforte and almond biscuits. Wine is where Siena comes closest, with Chianti Classico, Brunello and Vino Nobile all poured in the town's enoteche, though Etna's volcanic reds and whites give Catania a strong answer.

Siena is the richer city for sightseeing. Its whole medieval centre survives. The Duomo with its marble floor and Pisano pulpit, Duccio's Maestà and the Lorenzetti frescoes in the Palazzo Pubblico are major works of European art, and the contrade keep a civic tradition alive.

Catania appeals more for its buildings than its collections. It is a baroque city of black lava and pale limestone, with the vast monastery of San Nicolò l'Arena and Roman remains scattered through the streets. Its museums are modest, and the Feast of Sant'Agata in February is its great occasion.

Catania is clearly the city for going out. Its large student population fills the bars around Piazza Bellini and Via Gemmellaro until well after midnight, and in summer the beach clubs of La Playa turn into dance floors.

Siena winds down early. A usual evening is dinner, a glass of wine on the Campo and a stroll, and only on Palio nights do the streets stay full late.

Etna gives Catania the more dramatic outdoors. A smoking volcano about 3,300m high is less than an hour away, with craters, old lava flows and beech woods to walk. There is also the Alcantara Gorge to wade through, and you can snorkel or kayak around the sea stacks off the lava coast.

Siena's countryside is gentler and more pastoral, with the bare clay hills of the Crete Senesi and the rolling Val d'Orcia, both at their best in spring and autumn. It is excellent cycling country, with the strade bianche starting at the edge of town, but there are no high peaks and no coast.

Both make good bases, but Siena has more within reach. Florence, San Gimignano, Volterra, the Chianti villages, Montalcino, Pienza and the abbeys of Sant'Antimo and San Galgano are all easy outings, so a week of excursions never runs short.

From Catania the list is shorter but strong. Siracusa and Taormina are each about an hour away, and further out are the baroque towns of Noto and Ragusa Ibla and the Roman mosaics at Piazza Armerina. In both regions a car makes the smaller towns far easier.

Neither city is built around children, but Catania gives families more to do. The gently shelving sand at La Playa, a walk on Etna's old craters and the Etnaland theme park and water park fill the days, even if the traffic, narrow pavements and summer heat are tiring.

Siena is safe and mostly free of cars, but it has no attractions made for children, and its steep lanes are hard going with a pushchair. Older children enjoy climbing the Torre del Mangia, and families often do better in a farmhouse with a pool outside town.

Siena is the easier town to get around. Its centre is largely closed to cars and the sights are a few minutes' walk apart, though the climbs are steep. Escalators link the station to the upper town, and buses run to Florence.

Catania's compact centre along Via Etnea is easy on foot, but beyond it the single metro line, slow buses and heavy traffic make things harder. In both places the countryside really needs a hire car, and in Catania parking in the centre is a struggle too.

Neither city is a shopping destination, and in both the best things to buy are edible. Catania has a little more to offer: the chains along Via Etnea, the noisy daily market of La Fiera, and Bronte pistachio cream, Etna wine and Caltagirone ceramics to take home.

Siena's shopping is quieter: clothing and leather shops on Banchi di Sopra, majolica, contrada scarves, panforte and pecorino, and a large weekly market by the Fortezza Medicea.

Catania is the cheaper stay. Street food makes a full meal for little money, trattorias and guesthouses in the old town are reasonable for most of the year, and the churches are free to visit. Summer rooms, sunbeds and Etna summit tours do add up.

Siena costs more. There are few rooms inside the walls, and the cathedral complex and civic museums each charge for entry. A simple osteria lunch is good value, and staying in an agriturismo or a nearby town can bring the cost down.

Catania has the bigger stage. Bellini's home city has a grand opera house with a full season of opera and concerts that visitors can attend, and small companies keep the Sicilian puppet theatre of knights and Saracens alive.

Siena's music is more specialised: summer concerts by the Accademia Chigiana in palaces and churches, performances by Siena Jazz, and drama at the Teatro dei Rinnovati and the Teatro dei Rozzi. For opera, you have to go to Florence.

Siena is far better for rest, thanks to the hot springs around it. Rapolano Terme is about half an hour away, and further south are the steaming medieval bath of Bagno Vignoni and the free limestone pools of Bagni San Filippo, which pair well with a farmhouse stay.

Catania has no tradition of thermal baths and a noisy centre, and its spas are mostly in hotels on the coast and on Etna. What it does offer is a slow daily rhythm of long lunches and the evening passeggiata.