Volcanism
Iceland has a high concentration of active volcanoes. There are about 130 volcanic mountains, of which 18 have erupted since the settlement of Iceland.
High concentration of volcanic activity is due to a combination of the island's position on the Mid-Atlantic Ridge and a volcanic hotspot underneath the island. The island sits astride the boundary between the Eurasian and North American Plates, and most volcanic activity is concentrated along the plate boundary, which runs across the island from the south-west to the north-east of the island.
Important volcanos
In the south west of the country: Hekla, Mýrdalsjökull with Katla, Eldgjá and the Laki craters, Öræfajökull, Snæfellsjökull
Off the south coast in the Vestmannaeyjar archipelago are the recently-active Surtsey, and Eldfell on Heimaey
In the north of the country and in the interior: the glacier Vatnajökull with Bárðarbunga, Grímsvötn and Kverkfjöll, Krafla, Askja and Herðubreið.
Completed list of volcanoes in Iceland (Popup to Wikipedia)
