Silfra is a rift formed in the divergent tectonic boundary between the North American and Eurasian plates and is located in the Þingvallavatn Lake in the Þingvellir National Park in Iceland.
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.