The Golden Circle is a tourist route in southern Iceland, covering about 300 km looping from Reykjavík into the southern uplands of Iceland and back. It is the area that contains most tours and travel-related activities in Iceland. The term for the "Golden Circle" was a marketing tactic developed by the Icelandic Tourism board to improve travel. The three primary stops on the route are the Þingvellir National Park, the Gullfoss waterfall, and the geothermal area in Haukadalur, which contains the geysers Geysir and Strokkur, which erupts every 10-15 minutes. Though Geysir has been mostly dormant for many years, Strokkur continues to erupt every 5–10 minutes. Other stops include the Kerið volcanic crater, the town of Hveragerði, Skálholt cathedral, Bruarfoss, Friedheimar Tomato Restaurant, and the Nesjavellir and Hellisheiðarvirkjun geothermal power plants.