Iceland’s highest mountain, Hvannadalshnúkur (2110m), pokes out from Öræfajökull, an offshoot of Vatnajökull. This lofty peak is actually the northwestern edge of an immense 5km-wide crater – the biggest active volcano in Europe after Siciliy's Mt Etna. It erupted in 1362, firing out the largest amount of tephra in Iceland’s recorded history. The region was utterly devastated – hence its name, Öræfi (Wasteland).
In late 2017 and 2018, scientists detected increased activity in the volcano under Öræfajökull (the glacier and volcano share the same name). The volcano has been dormant for some 250 years, but is recognised as one of Iceland's most powerful.