Krafla, Viti crater от E.K.111

Krafla includes one of the two best-known Víti craters of Iceland (the other is in Askja). The Icelandic word "víti" means "hell". In former times, people often believed hell to be under volcanoes. The crater Víti has a green lake inside of it. The Mývatn fires occurred between 1724–29, when many of the fissure vents opened up. The lava fountains could be seen in the south of the island and a lava flow destroyed three farms. Between 1975 and 1984 there was a volcanic episode within the Krafla volcano. It involved nine volcanic eruptions and fifteen uplift and subsidence events. This interrupted some of the Krafla drillfields. During these events a large magma chamber emerged. (Wikipedia)