Etna is not one summit but a field of craters, and it changes: what you walk on this year may have arrived the winter before last. The lower cones can be walked freely; the summit area is a different matter and is done with authorised mountain guides, because the mountain is monitored and the rules move with it.
The south side goes up from Rifugio Sapienza and the Silvestri craters; the north side from Piano Provenzana, through forest and old flows.
Lava tubes — caves left by flowing lava — are a cold, dark counterpoint to the ash outside, and are done with lamps and a guide.
It is a mountain, not an attraction: temperature drops sharply with altitude, the wind is real, and the weather at 3,000 metres is not the weather in Catania.
The catalogue is open but still being filled, one business at a time, by hand. If you run something around Etna, this is the moment to be among the first.