"the tourist guides tell you the age of mountains you see like in other countries they tell you the age of buildings."
That is a wonderful observation, Wolfgang. It says so much about Iceland.
Much of Iceland is aged in the thousands of years. Where I grew up, the rocks are aged in the hundred millions of years, and when we went north for vacation, the rocks were aged in the thousand-millions.
So to me it is very strange to look at a landscape, as the Icelanders do, and know exactly how it came into being.