First we drove past Þingvallavatn towards Þingvellir National Park, where Alþing, the general assembly of the national parliament, was established around 930 AD and continued to convene there until 1798. We saw the Mid-Atlantic Ridge that rises above sea level, where the North American plate meets the Eurasian plate; some of the lava rocks still had ocean wave patterns on it.
The most impressive area of the park was Lögberg (the law rock); during the Icelandic Commonwealth period (930 - 1262), this was the hub of the meeting.
Last night I had perused a website that discussed the THING Project, as well as other international THING sites, and coincidentally this afternoon I found a very interesting looking book in one of the Þingvellir visitor centers: Things in the Viking World, edited by Olwyn Owen; it discussed "things" - assembly sites that had spread across northwest Europe as the result of the Viking diaspora and Norse settlements in Norway, Iceland, the Faroe Islands, the Isle of Man, and three different locations in Scotland. It seems to be in very limited print, so I'm glad I had found a copy.
On we drove to Haukadalur, the geothermically active valley that includes the geysers Geysir and Strokkur, a fountain geyser. Walking up to the area where the geysers were located, we came across lots of steam rising, and the strong smell of sulphur.
Our last stop of the day was Kerið, a volcanic crater lake, one of several in what's known as the Western Volcanic Zone; it's approximately 3,000 years old and the lake itself generally ranges in depth from about 23 to 46 feet deep.