Blesi Hot Spring is situated in the Geysir Geothermal Field in Haukadalur, Iceland.’ The word “Blesi” means “Blaze”. The Geysir field is found at the northern side of the southern lowlands, at a height of 105-120 m (~344-393 ft) above sea level. There is no charge for entrance.
Blesi is composed of two large basins, separated by a strip of land. The southern-lying spring is deep, clear and boiling hot water which flows across the strip of land into the second, northern basin which is a vivid azure colour. With no natural source of its own, these waters are comparatively cold, at around 40°C (104°F). The colour of the water is caused by dissolved silica.
There are records from the last century of travellers bathing and washing their clothes in the brook coming from Blesi, but today it is only a trickle. Its waters are diverted from time to time into Fata, a neighbouring pool, which is allowed to heat. Soap is then added to stimulate eruptions of spouting hot water. Blesi was last observed to boil vigorously in 2000, reaching nearly a metre high.
Blesi is considered to be the most beautiful of the geothermal features found here, but for environmental reasons, it is not permitted to bathe in it.