Strokkur (Icelandic for "churn") is a very reliable fountain geyser located in a geothermal area beside the Hvítá River in Iceland in the southwest part of the country, east of Reykjavík. It is one of Iceland's most famous geysers, erupting once every 6–10 minutes. Its usual height is 15–20 metres, although it can sometimes erupt up to 40 metres high.