Dortmund-Syburg, Blick zum Asenberg und zum Ebberg

The Ardey Hills (german: Ardeygebirge or ''Ardey'') are a range of wooded hills, up to ,
/ref> in the territory of the city of Dortmund 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 town ...

and

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

in the German state of

North Rhine-Westphalia North Rhine-Westphalia (german: Nordrhein-Westfalen, ; li, Noordrien-Wesfale ; nds, Noordrhien-Westfalen; ksh, Noodrhing-Wäßßfaale), commonly shortened to NRW (), is a state (''Land'') in Western Germany. With more than 18 million inha ...

. The hills form part of the eastern Rhenish Massif 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 stand ...

, 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 nor ...

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 an mean outflow near the mouth into the lower Rhine of . Description The Emscher h ...

Depression and Hellwegbörde in the north from the

Süder Uplands The Süder UplandsSauerland 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 land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sc ...

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

, 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 l ...

(), 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 reservoirs Hengsteysee and Harkortsee has earned it the nickname ...

to generate electricity from

hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of a w ...

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 the ...

Holzwickede Holzwickede () is a municipality in the district of Unna in North Rhine-Westphalia, Germany. It is twinned with Weymouth, Louviers and Colditz Colditz () is a small town in the district of Leipzig, in Saxony, Germany. It is best known for Co ...

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 mountainous ...

, Dortmund,

, Wetter and

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

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 average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardise ...

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

Klusenberg The Klusenberg is, at , the highest elevation on the territory of the city of Dortmund. The Klusenberg part of the Ardey Hills lies west of the Hohensyburg The Syberg is a hill in the Ruhr in the southern part of Dortmund, 240 m above Normalnul ...

(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 sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

and

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

(argillaceous shales) as well as

grauwacke Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lit ...

s from the Carboniferous 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 glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at La ...

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 gre ...

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, which will typically contain 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 ...

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 Dortmund 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. Traces of historic woodland usages like

coppicing Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeate ...

wood pasture Silvopasture (''silva'' is forest in Latin) is the practice of integrating trees, forage, and the grazing of domesticated animals in a mutually beneficial way. It utilizes the principles of managed grazing, and it is one of several distinct forms ...

and

charcoal burning A charcoal burner is someone whose occupation is to manufacture charcoal. Traditionally this is achieved by carbonising wood in a charcoal pile or kiln. Charcoal burning is one of the oldest human crafts. The knowledge gained from this industr ...

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 Landforms of North Rhine-Westphalia Natural regions of the Süder Uplands