Kamencové jezero (

Alum An alum () is a type of chemical compound, usually a hydrated double salt, double sulfate salt (chemistry), salt of aluminium with the general chemical formula, formula , such that is a valence (chemistry), monovalent cation such as potassium ...

Lake) is a lake in the municipal area of

Chomutov Chomutov (; ) is a city in the Ústí nad Labem Region of the Czech Republic. It has about 47,000 inhabitants. There are almost 80,000 inhabitants in the city's wider metropolitan area. The historic city centre is well preserved and is protected as ...

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

. It is

artificial Artificiality (the state of being artificial, anthropogenic, or man-made) is the state of being the product of intentional human manufacture, rather than occurring naturally through processes not involving or requiring human activity. Connotati ...

in that it came into being due to 18th century

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

. Kamencové jezero, at an altitude of , was caused at the end of the 18th century by flooding the mines used between the 16th and 18th centuries. It occupies an area of 15.95 ha and the maximum depth is 3.4 m. The high content (about 1%) of

alum An alum () is a type of chemical compound, usually a hydrated double salt, double sulfate salt (chemistry), salt of aluminium with the general chemical formula, formula , such that is a valence (chemistry), monovalent cation such as potassium ...

in the water from Alum Lake prevents the lake from the growth of weed and anabaena. For that reason it is very frequently visited in the summer months.

References

Artificial lakes of the Czech Republic Geography of the Ústí nad Labem Region Chomutov {{ÚstíNadLabem-geo-stub