The Great Þjórsá Lava (Icelandic: Þjórsárhraunið mikla [ˈθjour̥sˌaur̥ˌr̥œiːnɪð ˈmɪhkla]) is the largest lava flow in Iceland (by both area and volume) and the largest lava that is known to have erupted in a single eruption in the Holocene. It belongs to a group of lavas known as the . It was erupted in the Veiðivötn region, Central Iceland, 8600 years BP (6600 BC). The crater area is covered by younger lavas and eruptives. The Þjórsá Lava does not appear on the surface until 70 km downstream of its supposed crater area.