THE ANCIENT ICELAND.

In geological terms, Iceland is a young Island. It started to form about 20 million years ago from a series of volcanic eruptions on the Mid-Atlantic Ridge, where it lies between the North American and Eurasian plates that spread at a rate of approximately 2.5 centimeters per year.
Iceland remained, for a long time, one of the world's last larger islands uninhabited by humans (the others being New Zealand and Madagascar). The exact date that humans first reached the Island is uncertain.
The Iceland is one of the most active volcanic regions in the world, with eruptions occurring on average roughly every 3 years (in the 20th century 39 volcanic eruptions occurred on and around). The hotspot is partially responsible for the high volcanic activity which has formed the Island of Iceland. The first documented eruption in 939 was the largest flood basalt in historic time. An estimated 18km3 of magma poured out of the earth. Evidence from tree rings from around the Northern Hemisphere indicated that the eruption caused the summer of 940 to be one of the coolest summers in 1,500 years. Summer average temperatures in places as Central Europe, Scandinavia, Canada, Alaska, and Central Asia were lower than normal.
The first permanent settler in the Island is usually considered to have been a Norwegian chieftain named Ing'Olfr and his wife, Hall'Veig  Fro'Oad'Ottir, together with his brother Hj'Orl'Eif. A medieval Icelandic written work describes in considerable detail the settlement (Land'Nam) of Iceland by the Norse in the 9th and 10th CE. The people were primarily of Norwegian, Irish and Scottish origin. Some of the Irish and Scots were slave and servants of the Norse chiefs, according to the sagas of Icelanders, the Land'Nama'Bok, and other documents.
The traditional explanation for the exodus from Norway is that people were fleeing the harsh rule of the Norwegian king Har'Ald  Fair'Hair. He reigned from 872 to 930 CE.
The settlers worshipped the Norse gods, among them Odin, Thor, Freyr and Freyja. By the 10th CE, political pressure from Europe to convert to Christianity mounted. In the year 1,000 CE, as a civil war between the religious groups seemed to arouse strongly in debating which religion they should practice: Norse or Christianity, the established assembly (Al'Thing=Al'Pingi) appointed one of the chieftains, Thor'Geir  Lj'Osvet'Nin'Gag'Odi (law speaker from 985 to 1001), to decide over the matter. Thor'Geir himself a Norse priest, decided in favor of Christianity after a day and night of silent meditation under a fur blanket. Under the compromise, Norse religion could still be practiced in private and several old customs were retained. After his decision, Thor'Geir himself converted to Christianity. Upon returning to his farm, he is said to have thrown the idols of his gods into a nearby waterfall, for which it is now known in Icelandic as the "waterfall of the gods" (Goda'Foss).
Iceland is unusually suited for waterfalls. The Island has a North Atlantic climate that produces frequent rain and snow and a near-Arctic location that produces large glaciers, whose summer melts feed many rivers. As a result, it is home to a number of large and powerful waterfalls.