Thank you sayalio, the whole area is lava from the Snaefellsnes Glacier wich is a active volcano.
Do you remember Jules Verne's novel "Voyage to the center of the earth", the entrance was the volcano's crater ;-)
Thanks again for your kind words and comments dear Torben, this is a big lava area from the famous
volcano Snaefellsnes glacier, remember Jules Verne Jorney to the center of earth ;-)