Geysir hotspring and Strokkur

The Great Geysir

The earliest written accounts of hot springs in Haukadalur date from the thirteenth century. Their behaviour has changed repeatedly, often following earthquakes. A record from 1630 describes eruptions so powerful that the valley appeared to tremble, while later accounts made Geysir one of Iceland’s most celebrated natural phenomena.

At his strongest, Geysir could send water and steam tens of metres into the air. His activity gradually became less dependable during the nineteenth century, and he largely stopped erupting in 1916. He briefly returned to activity in 1935, and for a time people encouraged eruptions by adding soap to the spring. That practice belongs to Geysir’s history and is now strictly prohibited.

Earthquakes in June 2000 awakened Geysir again, initially producing several eruptions a day. The activity gradually declined, although occasional eruptions have occurred since then; the latest recorded eruption was in 2016. Whether he will one day enter another active period is impossible to know. Geysir has never followed a timetable made for visitors. His long silences and sudden responses to changes below ground are part of his character.

Strokkur — the active geyser

Strokkur lies only a short walk from Geysir and now provides the eruptions for which the area is famous. It normally erupts about every ten minutes, although the interval and strength vary. A typical eruption rises to around 20 metres, while stronger eruptions can climb higher.

The process begins below the visible pool. Groundwater descends through cracks in the rock and is heated by the geothermal system. Pressure at depth allows the water to become hotter than its normal surface boiling point. As steam begins to form, water is pushed upwards, pressure falls and part of the water flashes rapidly into steam. The expanding steam drives the column of water out of the vent.

Immediately before an eruption, the surface often draws back and then swells into a clear blue dome. It lasts only a moment before breaking into the rising jet. The water at the surface is approximately 90–95°C, and the eruption may come as a single burst or as two or more closely spaced jets.

Strokkur was first recorded after an earthquake in 1789 opened its conduit. Its activity changed during the nineteenth century and eventually declined when the conduit became blocked. In 1963, it was cleared from the bottom of the basin on the recommendation of the Geysir Committee. Strokkur has erupted regularly ever since.

Blesi and the geothermal field

Geysir and Strokkur are only two features within the wider geothermal field. The developed paths lead past steaming ground, mineral deposits and several named springs, including Blesi, Fata, Konungshver, Litli-Geysir, Litli-Strokkur and Smiður.

Blesi is among the most distinctive. It consists of two connected pools that can appear strikingly different: one intensely blue and the other clearer or more subdued in colour. The blue appearance is associated with fine silica suspended in the water and the way it scatters light. The contrast changes with light, weather and viewing angle, but it gives Blesi a visual presence quite unlike the explosive display of Strokkur.

The geothermal field was protected as a natural monument in 2020. The protection covers the hot springs and other geothermal formations, their mineral deposits and the landscape around them. It also recognises the area’s exceptional place in Icelandic natural history and in the international language of geothermal phenomena.

Visiting the geothermal area

Remain on the developed paths and respect all barriers and signs. Never touch the water or place stones, coins, soap or any other substance in the springs. Strokkur’s spray follows the wind, so stand on the side from which the wind is blowing rather than directly downwind, and keep children close.

Drone flights are prohibited within the Geysir geothermal area. The restriction took effect in May 2026.

• The English word geyser derives from the name Geysir.
• Geysir is largely dormant, while Strokkur normally erupts about every ten minutes.
• Strokkur is a fountain geyser: it erupts through a pool rather than from a built-up mineral cone.
• Earthquakes have repeatedly altered the activity of the hot springs in Haukadalur.
• Geysir’s latest recorded eruption occurred in 2016.
• The geothermal field has been protected as a natural monument since 2020.