Þingvellir is situated on the northern shore of Þingvallavatn, the biggest lake of Iceland. The river Öxará traverses the national park and forms a waterfall at the Almannagjá, called Öxaráfoss. Together with the waterfall Gullfoss and the geysirs of Haukadalur, Þingvellir is part of the most famous sights of Iceland, the Golden Circle.