Two million litres of hot mineral water bubble every day from the Wiesbaden hot springs - Kochbrunnen, Große und Kleine Adlerquelle, Salmquelle, Schützenhofquelle and Faulbrunnen. With a source temperature of about 67 °C, they are some of the warmest springs in Europe.

In the city centre, the water rises from a depth of 2,000 metres to the surface. This gift of nature has not only a pleasant effect when bathing, inhaling and drinking. The stored heat can also be used very well to heat houses and buildings. The Wiesbaden thermal water is thus a regenerative source of energy that is almost inexhaustible and, in this form, unique throughout Europe. Up to 850 tonnes of carbon dioxide emissions can be avoided every year through the use of thermal water. Currently, some 440,000 cubic metres of thermal water with a heat potential of 16.8 gigawatt hours are produced per annum.