I know Vulcano well. We've been to the summit (it's about 1600 feet) and we've relaxed by its famous, stinking mud pool, declining to enter it, unlike lots of other people there. There is much sulphurous effusion going on at the top. Fumaroles and stuff. Scary in several places. It's been out of bounds for several years due to increased volcanic activity. It's last eruption was in the late 1880s and it was quite devastating. Try to ascend it and you could be fined €500. There's a lot going on round there on land and at sea, most of it excitingly smelly. It doesn't have a great reputation as a good place for a holiday. You can see Stromboli from the summit and the view is glorious. We stayed on the next-door island of Lipari. Quite a lot of the film Il Postino was made on Salina, another close-by island, which produces the best capers in the world. Go and have a look, and don't let the microbes bite you. Another volcano famous for a microbe is La Solfatara at Pozzuoli, near Naples. Geysers, hot springs and hot mud pools are fertile ground for looking for thermophilic bacteria, and one was discovered new to science at Solfatara. I've been there too and it's mightily impressive with its bubbling mud, hot ground and fierce fumaroles. You can't go there any more either, following a tragic accident there in 2017 in which a young boy and his parents died after an unfenced part of the crater floor collapsed. Solfatara is in the large caldera called the Campi Flegrei, or the Fiery Fields, just a few miles from Naples and Vesuvius (been up there too!). It's a supervolcano that's been on high alert for several years following an increase in ground uplift and other seismic activity.