You can hear the gurgles, coughs, and explosions of the Stomboli lava tube clearing its irritable throat before you reach the southwest edge of the caldera at 3000 feet. The guided hikes, all the way from sea level, of course, are timed to put you on the ridge at dusk after a brief stop to put on dry shirts, jackets, and helmets. The eruptions are a thousand feet below you because of the collapse of the northwest wall of the crater 13,000 years ago. Stromboli is the archetype of the stombolian volcano, a tube in almost continuous small eruption
The horseshoe of fire above is a constant. Every ten to twenty minutes there are explosions like the one I did a bad job of photographing below as bubbles of gas are explosively released from solution and throw magma hundreds of feet into the air. Most come from the main vent, but occasionally a side vent flares with fire and red hot pumice. Every few years there are larger eruptions, which can throw lava bombs dangerously close to the small town on the island and create lava flows which reach the sea.
As you can see from the gps map below, the route up (about three hours) is a series of switchbacks),mostly on loose rock. We worried that we wouldn't be able to keep our footing coming down, even with our headlamps (the guide didn't speak English so we may have missed some explanations). But, when we started down after an hour on top, we went straight down in an almost rock-free cinder and ash slide; this semi-skiing technique of long steps, heal first, then a slide is easy to learn and easy to execute even on very tired legs. We were down in a little over an hour.
Where the path down went through vegetation, it had been worn shoulder-deep by walkers and water. But worrying about man-caused erosion on the cone of an active volcano is hubris.