The Ardey Hills ( or ''Ardey'') are a range of wooded hills, up to ,
/ref> in the territory of the city of

Dortmund Dortmund (; ; ) is the third-largest city in North Rhine-Westphalia, after Cologne and Düsseldorf, and the List of cities in Germany by population, ninth-largest city in Germany. With a population of 614,495 inhabitants, it is the largest city ...

and the districts of

Ennepe-Ruhr-Kreis The Ennepe-Ruhr-Kreis is a district in the center of North Rhine-Westphalia, Germany. It is part of the southern Ruhr urban area and has ca. 324,000 inhabitants (2012). The district's seat (capital city) is Schwelm; the largest of its nine towns ...

and

Unna Unna () is a city of around 59,000 people in North Rhine-Westphalia, Germany, the seat of the Unna (district), Unna district. The newly refurbished Unna station has trains to all major cities in North Rhine Westphalia including Dortmund, Köln H ...

in the German state of

North Rhine-Westphalia North Rhine-Westphalia or North-Rhine/Westphalia, commonly shortened to NRW, is a States of Germany, state () in Old states of Germany, Western Germany. With more than 18 million inhabitants, it is the List of German states by population, most ...

. The hills form part of the eastern

Rhenish Massif The Rhenish Massif, Rhine Massif or Rhenish Uplands (, : 'Rhenish Slate Uplands') is a geologic massif in western Germany, eastern Belgium, Luxembourg and northeastern France. It is drained centrally, south to north by the river Rhine and a few ...

and, to a lesser extent, to the Berg-Mark Hills (''Bergisch-Märkisches Hügelland'').

Geography

Location

The Ardey Hills, together with the

Haarstrang The Haar () or Haarstrang is a ridge of hills on the southern edge of the Westphalian Basin in the German state of North Rhine-Westphalia. From a natural region perspective it is the southern, submontane part of the Hellweg Börde, which stan ...

, run from east to west, separating two major natural units: the

Westphalian Lowland The Westphalian Lowland, also known as the Westphalian Basin is a flat landscape that mainly lies within the German region of Westphalia, although small areas also fall within North Rhine (in the extreme southwest) and in Lower Saxony (on the no ...

including the

Emscher The Emscher () is a river, a tributary of the Rhine, that flows through the Ruhr area in North Rhine-Westphalia in western Germany. Its overall length is with a mean outflow near the mouth into the lower Rhine of . Description The Emscher ha ...

Depression and Hellwegbörde in the north from the Süder Uplands and lower

Sauerland The Sauerland () is a rural, hilly area spreading across most of the south-eastern part of the States of Germany, German federal state of North Rhine-Westphalia, in parts heavily forested and, apart from the major valleys, sparsely inhabited. ...

in the south, the Ardey being counted as part of the Süder Uplands and the Haarstrang the Westphalian Lowland. From a

topographical Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary scienc ...

perspective, the Ardey Hills are the western foothills of the sparsely wooded and mainly agricultural Haarstrang. However it is different, not only from a cultural landscape point of view, but also geologically (a decisive factor being the

carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

boundary near the surface). In the north, on the territory of the city of

, the Ardey Hills descend gradually into the plain of the

in the area of Münsterland. To the south and west they are bounded by the

River Ruhr __NOTOC__ The Ruhr () is a river in western Germany (North Rhine-Westphalia), a right tributary (east-side) of the Rhine. Description and history The source of the Ruhr is near the town of Winterberg in the mountainous Sauerland region, at a ...

, their rugged slopes often dropping steeply into its valley. On those slopes the point where there is the maximum 165.2 mPumpspeicherkraftwerk Koepchenwerk (Herdecke) auf rwe.com
height difference, from the upper storage basin (ca. ) to the

Hengsteysee The Hengsteysee (Lake Hengstey) is a reservoir on the Ruhr river between the cities of Hagen, Dortmund and Herdecke, North Rhine-Westphalia, Germany. It was built in 1929 and is one of five reservoirs on the Ruhr. The reservoir is about long an ...

(), is used by the pumped-storage power station of ''Koepchenwerk'' in

Herdecke Herdecke () is a town in the district of Ennepe-Ruhr-Kreis, North Rhine-Westphalia in Germany. It is located south of Dortmund in the Ruhr Area. Its location between the two Ruhr (river), Ruhr reservoirs Hengsteysee and Harkortsee has earned it t ...

to generate electricity from

hydropower Hydropower (from Ancient Greek -, "water"), also known as water power or water energy, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, ...

Settlements

The following cities and towns are located in or at the Ardey Hills along the Ruhr − from east-northeast to west-southwest −:

Fröndenberg Fröndenberg (; Westphalian: ''Frönnenbiärg'') is a town in the district of Unna, in North Rhine-Westphalia, Germany. Geography Fröndenberg is situated in the Ruhr valley, approx. 10 km south-east of the district capital Unna, near th ...

Holzwickede Holzwickede () is a municipality in the district of Unna (district), Unna in North Rhine-Westphalia, Germany. It is twinned with Weymouth, England, Weymouth, Louviers and Colditz. Mayors *1969–1975: Josef Wortmann *1975–1989: Heinrich Sch� ...

Schwerte Schwerte (; Westphalian: ''Schweierte'') is a town in the district of Unna, in North Rhine-Westphalia, Germany. Geography Schwerte is situated in the Ruhr valley, at the south-east border of the Ruhr Area. South of Schwerte begins the mountain ...

, Wetter and

Witten Witten () is a city with almost 100,000 inhabitants in the Ennepe-Ruhr-Kreis (district) in North Rhine-Westphalia, in western Germany. Geography Witten is situated in the Ruhr valley, in the southern Ruhr area. Bordering municipalities * Bochum ...

Elevations

The highest point in the Ardey Hills is the long ridge of ''Auf dem Heil'', which rises in the territory of

west of the town itself. This and the other high points in the Ardey are shown below in order of height (m) above

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

(NN): *Auf dem Heil (273.8 m),

* Klusenberg (254.3 m), Dortmund-Syburg * Ahlenberg (247.5 m),

*Wartenberg (246.1 m),

* Syberg (245.4 m), Dortmund-Syburg *Harkortberg (231.5 m), Wetter * Ebberg (222.3 m),

*Rehberg (197.9 m),

* Hohenstein (ca. 146 m),

Geology and history

Predominantly acidophilous

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

(argillaceous shales) as well as

grauwacke Greywacke or graywacke ( ) is a variety of sandstone generally characterized by its hardness (6–7 on Mohs scale), dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or sand-size lithic fragments set i ...

s from the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

form the geological base of the Ardey Hills. They are the source of the Ruhr Sandstone which is extracted in large quarries. The Ardey and Haarstrang together were on the edge of the northern

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice s ...

from the last

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

Landscape

Along the Ruhr the Ardey has a decidedly hilly character with large height differences, steep, rocky slopes and deep

V-shaped valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a ve ...

s. Seen from the north and east the Ardey Hills have a gentler appearance. Here there are gently curved hilltops covered in woods and meadows. Due to its proximity to the city of

and town of

the northern edge of the hills is a popular residential area and, as a result, densely populated. The ridges (''Eggen'' or "edges") of the Ardey are covered by beech woods. Its slopes are incised by the V-shaped valleys of small streams, known as ''Seipen'' and divided into small landscape units. The Ardey Hills are an old

cultural landscape Cultural landscape is a term used in the fields of geography, ecology, and heritage studies, to describe a symbiosis of human activity and environment. As defined by the World Heritage Committee, it is the "cultural properties hatrepresent the c ...

. Traces of historic woodland usages like

coppicing Coppicing is the traditional method in woodland management of cutting down a tree to a tree stump, stump, which in many species encourages new Shoot (botany), shoots to grow from the stump or roots, thus ultimately regrowing the tree. A forest ...

, wood pasture and

charcoal burning Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ca ...

may still be found in many places today.

Walking

A particularly attractive section of the Ruhr Ridgeway (''Ruhrhöhenweg'') maintained by the Sauerland Mountain Club (''Sauerländischer Gebirgsverein'') runs along the heights of the Ardey Hills from the source of the Ruhr to its confluence. The path has many viewing points especially in the Ruhr valley. The Westphalian Way (''Westfalenweg'') also runs over the Ardey Hills.

References

{{Authority control Hill ranges of Germany Mountains and hills of North Rhine-Westphalia Natural regions of the Süder Uplands