Thermal Lake of H e v i z , Hungary (Hévíz Spa) Photographed by Ivan Szedo
2011.04.20. Heviz spa The Thermal Lake of Hévíz is the world’s largest biologically active natural thermal lake. It is located in a unique setting, a mere 6 km from the Lake Balaton, 198 km from Vienna and 193 km from Budapest. The lake’s formation goes back to ancient times. At the end of the Pannon-era (named after its sea), volcanoes broke up the layout of the Trans-Danube region. The first signs of volcanic activity were the heat sources, as was the eruption of Ancient ‘hévíz’ (i.e. ‘hot water/source’). Two systems of dikes were formed by the movement of the Earth crust in which precipitation was collected. This is how Lake Balaton was formed 22 thousand years ago, the time that marked the beginning of the Hévíz thermal lake’s history. The heat coming from the deeper layers of the Earth crust heats the waters locked inside the underground deposits, which means that the lake is also heated by geometric energies. The 4,4 ha water surface lake's source rich in minerals can be found 38 m deep in the cave, where tens of thousands of years old warm and cool karst waters are mixed. The lake’s exact depth did not use to be known, but authentic data shows that it is 38.5 m deep. Hévíz bathers have experienced that the water’s depth varies between 150 and 200 cm. You can stand up around the edges and sink thigh-deep into the softened and healing turf mud . The 3,8 ha lake Echo of New Zealand is second largest after Hévíz in terms of size, however it is unsuitable for bathing due to its water temperature (50-55 C).
2011.04.20. Heviz spa The wildlife of Hévíz thermal lake is unique due to its temperature and unique chemical composition. Some of the interesting wildlife and botanic species of Hungary can only be found in their natural habitat here. Algae, weeds (especially blue algae), sulphur bacteria, actynomycetales and agricultural weed. The micro-organisms and metabolism products of the water and mud contribute significantly to the healing force of the lake. The various strains of bacteria provide antibiotic and antiseptic effects. The most spectacular members of botanic life are water lilies. The native white water lily (Nymphaea alba) sub-species has been pushed out of the lake by today but still lives in the drains in large populations. Red water lilies (Nymphaea rubra var. longiflora) were planted between 1898 and 1906 by Sándor Lovassy, a teacher at the Academy of Economics of Keszthely. He experimented with the plantation of a number of species, but only the red water lily was viable. The lake has become a true home to this species since then. Water lily is a protected species of the lake, therefore they must not be disturbed and their flowers must not be broken off. The lake also has a versatile wildlife, , from tiny single cell organisms to vertebrates can all be found here. Water snails and fish live on plankton crabs, dragonflies and leaf and flower bugs as well as different moths water cleaning rotifers.