The Jet d'Eau (French pronunciation: [ do], Water-Jet) is a large fountain in Geneva, Switzerland, and is one of the city's most famous landmarks, being featured on the city's official tourism web site and on the official logo for Geneva's hosting of group stage matches in the 2008 UEFA Euro. Situated where Lake Geneva exits as the Rhône, it is visible throughout the city and from the air, even when flying over Geneva at an altitude of 10 kilometres (33,000 ft).
Five hundred litres (110 imp gal; 130 US gal) of water per second are jetted to an altitude of 140 metres (460 ft) by two 500 kW pumps, operating at 2,400 V, consuming one megawatt of electricity. The water leaves the 10 centimetres (3.9 in) nozzle at a speed of 200 kilometres per hour (120 mph). At any given moment, there are about 7,000 litres (1,500 imp gal; 1,800 US gal) of water in the air. Unsuspecting visitors to the fountain--which can be reached via a stone jetty from the left bank of the lake--may be surprised to find themselves drenched after a slight change in wind direction.
The first Jet d'Eau was installed in 1886 at the Usine de la Coulouvrenière, a little further downstream from its present location. It was used as a safety valve for a hydraulic power network and could reach a height of about 30 metres (98 ft). In 1891, its aesthetic value was recognised and it was moved to its present location to celebrate the Federal Gymnastics Festival and the 600th anniversary of the Swiss Confederation, when it was operated for the first time. Its maximum height was about 90 metres (295 feet). The present Jet d'Eau was installed in 1951 in a partially submerged pumping station to pump lake water instead of city water.
Since 2003, the fountain has operated during the day all year round, except in case of frost or particularly strong wind. It also operates in the evenings between spring and autumn, when it is lit by a set of 21 lights totaling 9 kW.
On 25 August 2016, the fountain celebrated its 125th anniversary at its present location.