Four days. That is the honest answer for Catania, and it arrives with a condition attached: you do not get to decide which day is which.
Most cities let you lay an itinerary out in advance and then follow it. Catania sits at the foot of an active volcano, and that volcano is both the reason most travellers fly into this particular airport and the one item on the list that can be withdrawn at a few hours' notice. The cable car above Rifugio Sapienza closes in high wind. The summit zone shuts for a day or two whenever Etna opens a new fissure and vents through it, which the operators themselves describe as ordinary behaviour rather than an emergency. Cloud can sit on the cone all morning and burn off by two, or sit there until dark.
So you plan this trip backwards. You commit to nothing on the mountain before you arrive, you read the forecast and the volcano bulletins on your first two mornings, and you spend the first genuinely clear day up there. Everything else Catania offers is flat, cheap, walkable and available at short notice, which makes it the ideal filler for whatever the weather leaves you. Below is how to fill it.
The booking that dictates all the others
Two routes go up the south side. The public bus is the cheap one: a single AST service leaves the square beside the central station area in the early morning, timetabled somewhere around a quarter past eight, takes roughly two hours, and starts back down in the middle of the afternoon, around half past four when last published. Expect to pay in the region of seven euros return, bought on board, and note the arithmetic: one bus up and one bus down means the mountain owns your entire day whether you want it to or not. The alternative is a hire car, a driver, or an organised excursion, all of which buy flexibility and cost considerably more.
Rifugio Sapienza, where the road ends, sits at about 1,910 metres. What you can do from there divides cleanly at a single altitude. Below 2,800 metres you need no permit, no ticket and no guide. Above it, a certified volcanological or mountain guide is mandatory under rules set by the Parco dell'Etna and the regional authority, and this is a genuine safety regime rather than a sales tactic: gas vents move after each paroxysm, flows reroute within hours, and the guides train with Italy's national geophysics and volcanology institute so that they can read conditions a visitor cannot. The historic shelter at Torre del Filosofo, at roughly 2,900 metres, is on the wrong side of that line.
The free options are better than they sound. The loop around the Silvestri craters, immediately by the car park, takes around an hour on level ground and puts you inside a cinder landscape straight away. The longer walk up Schiena dell'Asino climbs something like 600 metres over three or four hours and delivers the view that people pay for, the whole eastern flank of the caldera falling away beneath you. If you ride up instead, the cable car alone costs around fifty euros return at recently published rates, and the combined ticket that adds a four-wheel-drive shuttle and a short guided walk higher up runs to roughly eighty. A full guided trek to the active craters sits somewhere above that again. All of those figures move, so check them on the day.
Dress for a different climate than the one you left. Reckon on losing about ten degrees for every thousand metres you gain, which means layers, a wind shell, a hat and proper shoes even in high summer, plus sunglasses, strong sunscreen and more water than feels necessary. Before you commit, look at the cable car operator's own social channels and the institute's daily bulletin. Both will tell you more than any forecast app about whether today is the day.
Day one: the city at walking pace
Most arrivals land close to town. The airport shuttle bus into the centre costs around four euros and the ticket is typically valid across the network for about ninety minutes afterwards; a taxi to the centre runs on a fixed rate in the region of twenty-five to thirty euros. Once you are in, a single metro or bus ticket is about a euro for ninety minutes and a day pass around two and a half, but the historic centre is flat and tight enough that you may finish the trip having bought neither.
Begin in Piazza del Duomo, and notice the colour before anything else. The cathedral, the palaces, the paving and the elephant fountain that Catanians call u Liotru are all grey-black, because the city was flattened by the earthquake of 1693 and rebuilt at speed out of the only material lying around in quantity. That single fact explains the look of everything you will see for the next four days.
From there walk north up Via Etnea, the spine of the city, roughly three kilometres end to end and a comfortable forty minutes at a browsing pace. You pass Piazza dell'Universita, then Piazza Stesicoro, where a section of the Roman amphitheatre sits sunk below the modern street like an open trapdoor into the second century. Finish in the Villa Bellini gardens, partly because they are the pleasant end of the walk and partly for a practical reason: on a clear evening the terraces give you Etna, which is your first honest read on whether tomorrow is the mountain day. Opposite the garden gates, Pasticceria Savia has been trading since the 1890s and is the sensible place to learn what granita, cannoli and a properly made arancino are supposed to taste like, for a few euros.
For dinner, Me Cumpari Turiddu occupies the square many locals still call Piazza Spirito Santo, north of the core. Michelin listed it as a Bib Gourmand in the 2026 Italian guide, which is their shorthand for good cooking at a fair price, and the kitchen leans hard on Slow Food producers; there is a simpler bistro menu alongside the restaurant one and a bar that runs through the day. Book ahead. If you want something faster and cheaper, Fud Bottega Sicula built its reputation on Sicilian street food assembled from small island producers.
