Þingvellir National Park
Þingvellir (Thingvellir) is the National Park where the Althing, an open-air assembly representing the whole of Iceland, was established in 930 and continued to meet until 1798. Over two weeks a year, the assembly set laws - seen as a covenant between free men - and settled disputes. The Althing has deep historical and symbolic associations for the people of Iceland. The property includes the Þingvellir National Park and the remains of the Althing itself: fragments of around 50 booths built from turf and stone. Remains from the 10th century are thought to be buried underground. The site also includes remains of agricultural use from the 18th and 19th centuries. The park shows evidence of the way the landscape was husbanded over 1,000 years.
http://whc.unesco.org/en/list/1152
Thingvellir National Park is a cultural landscape representing mediaeval Norse/Germanic culture. It lies in the the southwest of Iceland near the peninsula of Reykjanes and the Hengill volcanic area.
The valley is one of the most important places in Icelandic history. In the year 930, the Althing, one of the oldest parliamentary institutions of the world, was founded. The Althing met yearly, where the Lawspeaker recited the law to all of the gathered people and decided disputes as well. Criminals were also punished at these assemblies; to this day, visitors can see the Drekkingarhylur ("drowning pool") in the river, where woman lawbreakers were drowned.
http://www.worldheritagesite.org/sites/thingvellir.html