The Atta Cave (german: Atta-Höhle) 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 made of porous stone * D ...

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 Calcareous sinter is a freshwater calcium carbonate deposit, also known as calc-sinter. Deposits are characterised by low porosity and well-developed lamination, often forming crusts or sedimentary rock layers. Calcareous sinter should not be conf ...

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 Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of whic ...

s. There are also many

stalactite A stalactite (, ; from the Greek 'stalaktos' ('dripping') via ''stalassein'' ('to drip') 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 an ...

stalagmite A stalagmite (, ; from the Greek , from , "dropping, trickling") 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 ...

s and

stalagnate A stalactite (, ; from the Greek 'stalaktos' ('dripping') via ''stalassein'' ('to drip') 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 an ...

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 geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

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 ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

then being laid down, caverns were formed over time by carbonic acid 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 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, depending on ...

s. The caves are also inhabited by

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". 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 bi ...

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