The Italian caldera volcano Campi Flegrei is located in the urban area of Pozzuoli and only 20 km away from Vesuvius. The name is derived from the Greek phlégein which means ‘to burn’. Freely translated, the name means “burning fields”. The name alone does not give a good idea! In fact, the Caldera volcano is often classified as a super volcano. The reason for this classification was a gigantic eruption about 37,000 years ago: ash deposits have been detected even at a distance of over 1000 km.