Þingvellir, a UNESCO World Heritage Site, lies in a rift valley that marks the crest of the Mid-Atlantic Ridge and the boundary between the North American and Eurasian tectonic plates. To its south lies Þingvallavatn, the largest natural lake in Iceland.
Thingvellir National Park was founded by law in 1930. The Act states that “Þingvellir at Öxará shall be a protected national shrine for all Icelanders.” In 2004 Þingvellir was added to the UNESCO World Heritage List. During the Old Commonwealth era (930-1262), The Lögretta (Law Council) was responsible for law making and the resolution of legal disputes. Laws were recited from memory every year to the assembly from the Lögberg (Law Rock)
The waterfall flows out the river Öxará, cascading in two drops over the cliffs of Almannagjá gorge, which marks the eastern boundary of the North American and Eurasian tectonic plates. The waterfall has a height of 13 metres (44 feet) and an average width of six metres (20 feet).