Bárðarbunga ([ˈpaurðarpuŋka]), Bardarbunga (Anglophone spelling), is a stratovolcano located under Vatnajökull, Iceland´s most extensive glacier. The second highest mountain in Iceland, 2,009 metres (6,591 ft) above sea level, Bárðarbunga is also part of a volcanic system that is approximately 200 kilometres (120 mi) long and 25 kilometres (16 mi) wide.