Lake Madum

Madum Lake
Water in Madum Lake in 2011. The lake's extremely pure and clear water supports a number of rare aquatic plants, including certain species of Lobelia.
Location	Rebild Municipality, Mariagerfjord Municipality, Denmark
Coordinates	56°02′13″N 9°47′24″E / 56.037°N 9.79°E / 56.037; 9.79Coordinates: 56°02′13″N 9°47′24″E / 56.037°N 9.79°E / 56.037; 9.79
Type	Kettle hole
Surface area	2.04 square kilometres (0.79 sq mi)
Average depth	3 metres (9.8 ft)
Max. depth	7.5 metres (25 ft)
Surface elevation	36 metres (118 ft)
Settlements	Skørping, Astrup

Madum Lake (Danish: Madum Sø) is the largest lake in the Himmerland peninsula of Jutland, Denmark. The lake covers an area of 2.04 square kilometres (0.79 sq mi), and has a depth of 7.5 metres (25 ft) at its deepest point. It is both an important bird sanctuary and a popular bathing spot.

Madum Lake most likely developed out of a glacial kettle hole – a hollow formed by the melting of glacial ice left by the Quaternary ice age. The lake formerly lay in heathland, but it is now located in Rebild Municipality, and is surrounded by the Rold Skov forest. To the north of the lake is a narrow forested belt, with birch as the dominant tree species. In the forest, common passerine birds dominate, along with buzzards, goshawks, sparrowhawks, long-eared owls, tawny owls, black woodpeckers, green woodpeckers and ravens. In winter months, whooper swans and merganser ducks can be seen around the lake.

Madum Lake and the surrounding forest are partly owned by three private interests – Lindenborg Gods, Nørlund and Willestrup Estate – with 25% of the forest falling under state ownership. There is public access, and it is possible to walk around the lake on a marked route. Public fishing and boating on the lake is prohibited. At the lake's eastern shore is a visitor parking space, from which extends a marked route to and around the Long Marsh – a large, well-preserved bog in the forest to the east.