The Iberg is a hill, 563 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 standardised g ...

, in the western

Harz mountains The Harz () is a highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The name ''Harz'' derives from the Middle High German ...

in the German state of

Lower Saxony Lower Saxony (german: Niedersachsen ; nds, Neddersassen; stq, Läichsaksen) is a German state (') in northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ...

. It lies north of

Bad Grund Bad Grund (Harz) is a town in the district of Göttingen, in Lower Saxony, Germany. It is situated in the western Harz, approx. 7 km west of Clausthal-Zellerfeld, and 10 km north of Osterode am Harz. Bad Grund is also the name of the ...

, above the Harz High Road. The Iberg is an old

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

that emerged in the

Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in Fra ...

Frasnian The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage. Major reef-building was under way during th ...

(

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 ...

) stages, that was created as an

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can gr ...

in the middle of the ocean, probably from the base of a

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

. The reef was mainly built by

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

s und

stromatoporoidea Stromatoporoidea is an extinct clade of sea sponges common in the fossil record from the Ordovician through the Devonian. They were especially abundant and important reef-formers in the Silurian and most of the Devonian.Stock, C.W. 2001, Stromat ...

. Later, as the

transitioned into the

Famennian The Famennian is the latter of two faunal stages in the Late Devonian Epoch. The most recent estimate for its duration estimates that it lasted from around 371.1 million years ago to 359.3 million years ago. An earlier 2012 estimate, still used b ...

, these reef-building organisms died out leaving the reef unfinished. During the

and Mississippian crevices emerged that were filled with

crinoid Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...

und

goniatite Goniatids, informally goniatites, are ammonoid cephalopods that form the order Goniatitida, derived from the more primitive Agoniatitida during the Middle Devonian some 390 million years ago (around Eifelian stage). Goniatites (goniatitids) survi ...

chalks. The Iberg is made entirely of limestone and

karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

ification has resulted in numerous caves. One of these, the Iberg Dripstone Cave is open to the public through guided tours. In the immediate vicinity is the Hübichenstein. On the northwestern slopes of the Iberg is a large

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 ...

quarry and a lime works. On the summit is the Albert Tower (''Iberger Albertturm'') and a restaurant for day trippers. There is also a checkpoint (no. 130) for the

Harzer Wandernadel The Harzer Wandernadel is a system of hiking awards in the Harz mountains in central Germany. The hiker (or mountain biker) can earn awards at different levels of challenge by walking to the various checkpoints in the network and stamping his or ...

. The ''Iberger Kaffeehaus'' on the northern slope was a popular restaurant and was also referred to as Bad Grund's Balcony (''Balkon Bad Grunds''). However it was the victim of arson on 28 February 2000 and has since fallen into rack and ruin.

References

{{Coord, 51, 49, 14, N, 10, 14, 58, E, type:mountain_elevation:563_region:DE-NI_dim:2500, display=title Hills of the Harz Hills of Lower Saxony

See also

References