Krafla volcano with a caldera 10 km wide located in the north of Iceland. Caldera was formed about 100,000 years before, as evidenced by the rhyolitic tuff formations of this period. In the recent past erupted from 1724 to 1729 and most recently in 1975-84. Caldera system crosses the watershed in north-south, which is the cause of all volcanic activity in the region.
(° source Wikipedia)