The lateral craters are cones of volcanic scoria formed during flank or eccentric eruptions of the volcano (not generated by the summit craters) but by eruptive fractures at lower altitudes. Etna has about 250 of them along its flanks and their number is increasing because with each explosive eruption these cones form upstream of the lava flow. They are on average about 100 meters high, made up of pyroclastic and incoherent material (ash, sand, lapilli, tuffs) and can often manifest themselves through the spectacular "button system", that is, several cones in succession aligned on the eruptive axis as if they were, in fact, buttons.

These craters usually generate the most destructive lava flows for inhabited centers. For example, the Monti Rossi of Nicolosi bear witness to the historic eruption of 1669 that destroyed villages and part of the city of Catania, up to the sea.

HIKING NOTES: During our excursions on Etna it will be possible to see many recent and ancient craters and climb to the top of some of these craters.