Vulcano Solfatara, Pozzuoli

Solfatara is a dormant volcano belonging to the volcanic area of the Campi Flegrei, believed by the ancients to be the entrance to the regions of Hell. It is noteworthy today on account of the explosions of sulphuric gases, at temperatures well over 160° C, as well as for the anhydrous carbon vapors and the smaller eruptions of boiling mud. During the nineteenth century it was a renowned spa, on account of its waters, natural saunas and hot mud; sulfur compounds were also extracted. It currently represents the epicenter of the cyclical rising and lowering of the base of the Campi Flegrei, known as bradyseism. Check website for visiting details.