The Atta Cave () or Attendorn Dripstone Cave (''Attendorner Tropfsteinhöhle'') in

Attendorn Attendorn () is a German town in the Olpe district in North Rhine-Westphalia. As of 2019 it had a population of 24,264. History The town's location was favoured by the good climate in the Attendorn-Elsper Limestone Double Basin (''Attendorn- ...

is one of the largest

dripstone cave Dripstone may refer to: *Hood mould or dripstone, an architectural feature for handling rain water * Dripstone, a type of speleothem (cave formation) that includes for example stalactites * Dripstone, a type of water filter A water filter remov ...

s in Germany. The cave was discovered during the quarrying of limestone at the Bigge Valley Limestone Works (''Biggetaler Kalkwerk'') on 19 July 1907 and was opened up by the owners to tourists that same year. Today the Atta Cave is the most-visited

show cave A show cave—also called tourist cave, public cave, and, in the United States, commercial cave—is a cave which has been made accessible to the public for guided visits. Definition A show cave is a cave that has been made accessible to ...

in Germany, receiving around 350,000 tourists per year, and is an important economic factor for the town. Amongst its attractions are numerous calc-sinter

flowstone Flowstones are sheetlike deposits of calcite or other carbonate minerals, formed where water flows down the walls or along the floors of a cave. They are typically found in "solution caves", in limestone, where they are the most common speleothe ...

drapes, colourfully tinctured by

iron oxide An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron ...

s. There are also many

stalactite A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension (chemistry ...

stalagmite A stalagmite (, ; ; ) is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites are typically composed of calcium carbonate, but may consist ...

s and

stalagnate A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension, or is ca ...

s. Several pieces of calcite crystal formations were moved into the public area of the cave in order to be displayed there.

History

The formation of the cave started in the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

period (about 400 million years ago) when the region of the present-day cave still lay in a bay of the sea. In the layers of

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

then being laid down, caverns were formed over time by

carbonic acid Carbonic acid is a chemical compound with the chemical formula . The molecule rapidly converts to water and carbon dioxide in the presence of water. However, in the absence of water, it is quite stable at room temperature. The interconversion ...

weathering caused by the rainwater seeping through it as well as mixed corrosion (''Mischungskorrosion''). An earthquake several thousand years ago broke several of the

speleothem A speleothem (; ) is a geological formation made by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depen ...

s. The caves are also inhabited by

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s that get into the cave through rock crevices in the hilltop. Other parts of the cave were discovered in 1985 by Elmar Hammerschmidt. The total length of the cave is 6,000 metres but it has not been completely surveyed. For the show cave section there is a roughly 500 m long circular tour. It is reached through a 90 metre long gallery through which visitors are guided. The original entrance is sealed today with a metal door. In one part of the cave, cheese is stored, a water curtain is supposed to help stop the smell spreading too far. The cave is still in private hands today. It has been criticised for its high entry charges and ban on photography. Jochen Duckeck: ''Die Attendorner Tropfsteinhöhle.''
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Sources

* Rainer Ahrweiler, Elmar Hammerschmidt: ''Attendorner Tropfsteinhöhle.'' In: Die Höhlen der Attendorn-Elsper Doppelmulde, Karst und Höhle 1991/92, VdHK München, ISSN 0342-2062, pages 25–36

References

{{Authority control Caves of Germany Limestone caves Karst formations of Germany Landforms of North Rhine-Westphalia Show caves in Germany Tourist attractions in North Rhine-Westphalia

History

See also

Sources

References