Geysir is the word that gave the world its geysers, and the original is still here, in the Haukadalur valley, a basin of steaming ground, blue pools and mineral-stained earth. The Great Geysir itself has been mostly dormant for many years, with only occasional activity, but its neighbour Strokkur obliges the crowds every few minutes, throwing a column of water high into the air with a deep gurgle and a sigh.
Approaching the area is straightforward. The road crosses open farmland and gentle hills with the distant glaciers of Langjökull and Hekla on the horizon, and the surface is generally smooth with moderate traffic. The park is a short walk from the parking, and the ground is hot and fragile, so stay on the paths. The smell of sulphur is unmistakable and the steam drifts across the road on cold days, which can be briefly confusing at speed.
The geology behind it is simple but spectacular. Water seeps deep into the volcanic rock, is heated by magma, and is forced back to the surface in explosive bursts. The mineral deposits form colourful crusts around the pools, and the hot springs make the surrounding ground steam in winter. The name comes from the Old Norse verb to gush, and the site has been described by travellers since the Middle Ages, and travellers have been describing it for centuries.
Nature around the area includes geothermal vegetation, with algae and mosses that thrive in the warm water, and in the surrounding countryside, Icelandic horses graze on the fields. Many visitors enjoy a break at the visitor centre across the road, which has food, shops and a decent cafe, and which is among the better-served stops on the Golden Circle.
Timing matters. Mid-morning to mid-afternoon the crowds are heaviest, and early or late is better for photographs. Be careful of wet ground and sudden spray, and of heavy gusts on the open plain.