Bárðarbunga (Icelandic pronunciation: [ˈpaurðarˌpuŋka]), is a stratovolcano located under Vatnajökull in Vatnajökull National Park which is 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.