The Leirhnj#250;kur area is a central volcano in the Krafla caldera, northeast Iceland. One hundred thousand years ago, there was a volcanic cone here that caved in after erupting. The caldera thus formed is now filled with younger volcanic material lying on a thin 2-3km crust, upon an active magma chamber.br/br/Krafla is a caldera of about 10#160;km in diameter with a 90#160;km long fissure zone, in the north of Iceland in the M#253;vatn region. Its highest peak reaches up to 818 metres and it is only 2km in depth. There have been 29 reported eruptions in recorded history.