|The treasure of Hévíz|
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).
The lake’s more developed wildlife consists of a few fish and amphibians besides tiny creatures and snails. The crucian carp (Carassius carassius) that likes living in the reed and mud is a natie to the lake, as are tench (Tinca tinca), carp bream (Abramis brama) and ide (Leuciscus idus), a fish that likes catching bugs on the water surface. Amphibians include frogs, pond terrapins (Emys orbicularis) and ducks. When Lake Balaotn freezes,mute swans (Cygnus olor), black-headed gulls (Larus ridibundus) and sometimes even Eurasian coots (Fulica atra) find rescue here. Mammals living in the area include the Eurasian water shrew (Neomys fodiens) that feeds on small fish and common shrew (Sorex araneus), who feeds on insects. There are three further species of fish living in the lake, namely mosquitofish (Gambusia affinis), mosquitos (Aedes vexans), goldfish (Carassius auratus), while the fish egg-eating bluegill lives in the drain.
These little creatures do not disturb bathers in the slightest, they can only be seen if one looks for them persistently.
Source: Hévíz and the surrounding area, Nereus Publishing Co., 2006.