Þingvellir (Thingvellir) is a historic site and national park in Iceland, east of Reykjavík. It's known for the Alþing (Althing), the site of Iceland's parliament from the 10th to 18th centuries. On the site are the Þingvellir Church and the ruins of old stone shelters. The park sits in a rift valley caused by the separation of 2 tectonic plates, with rocky cliffs and fissures like the huge Almannagjá fault.