Iceland has extensive volcanic and geothermal activity. The rift associated with the Mid-Atlantic Ridge, which marks the division between the Eurasian Plate and North American tectonic plates, runs across Iceland from the southwest to the northeast. This geographic feature is prominent at the Þingvellir National Park, where the promontory creates an extraordinary natural amphitheatre. The site was the home of Iceland's parliament, the Alþing, which was first convened in 930. It is a common misconception that Þingvellir is at the juncture between the North American and Eurasian continental plates. However, they are in fact at the juncture of the North American continental plate and a smaller plate (approx. 10,000 km2) called the Hreppar Microplate (Hreppaflekinn). From 1963 to 1967, the island of Surtsey was created on the southwest coast by a volcanic eruption.