pozzuoli, the super active volcano of the campi flegrei. the solfatara is the only visible mouth with its fumaroles

geology rock terrain cliff badlands wadi soil mountain ridge plateau ruins coast valley wall formation sea trail bedrock wilderness fumarole sulfuric mineral vapor hot bradyism active mystery heat clouds mountains crater fog hydrothermal solfatara pozzuoli thermal volcanic phenomena fumaroles super volcano eruption campi flegrei ecosystem caldera national park wildlife nature geyser hiking steam geothermal tourism outdoor water sky italy naples sulfur beautiful bison orange barren palpitation flegrei visible mouth