I also learned a great deal about the flora and fauna. When the first Vikings arrived from Norway in the tenth century, the island had no native land mammal except the arctic fox. Polar bears sometimes landed on the north of the island, but never took up permanent residency. The only native tree was the dwarf birch, which grows to about six feet. This is the source of one of the driver's best jokes. Q: "What should you do if lost in an Icelandic forest?" A: "Stand Up."
The Vikings brought in other species, including reindeer and horses. The horses are small, more like ponies, but do not tell an Icelander that. Call them horses, please. Farm animals, dogs, cats, mice, rats, and many different plant species have been imported over the centuries since the first human settlement. One particular import, the lupin, has taken over large swathes of the island.
The Golden Circle passes through a lot of beautiful landscapes, including the most spectacular waterfall I've ever seen, Gullfoss, on the Hvita (White) River. (Gullfoss)
Gullfoss is fed by Iceland's second largest glacier, and is considerably larger than Niagara Falls. The roar of the falls is certainly deafening. Gullfoss means "Golden Falls". The name derives from the fact that the sediment-laden water looks golden on sunny days. It drops 32 meters (105 feet) into the chasm below. It is the largest waterfall in Europe by volume, if one considers Iceland part of Europe. That brings me to the second highlight of the Golden Circle: Thingvellir.
Thingvellir National Park stands at the place where two tectonic/continental plates meet: The Eurasian and the North American. Iceland is thus partly in North America and partly in Europe.
Thingvellir is a geologist's paradise. But its importance is not only geological. It is also significant in Icelandic history. Starting back in AD 930, the national assembly (Althing) met here, and continued to do so until 1798. The name Thingvellir means something like "Parliament (or Assembly) Fields." (Thingvellir)
Thingvellir lies in a rift valley that marks the crest of the Mid-Atlantic Ridge, and the evidence of geologic activity is all around you.
Geysir (from which we get "geyser") is a hot spot where Iceland blows off a lot of steam. The place is named after the largest of the geysers in the park, Geysir. It erupts infrequently nowadays, sometimes not for years, but its recorded eruptions have sometimes reached heights of more than 100 meters. Other geysers nearby are rather tame most of the time, just bubbling away. Good places to boil some eggs. But one geyser, called Strokkur, erupts about every 6-10 minutes, which is good for tourists on a tight schedule. Strokkur sends a plume of hot water about 30 meters into the air. Thankfully, the water cools a good bit by the time it returns to earth, because it is hard to avoid being hit by some of it when up close.