Lake Gentofte Sø (on almost 27 ha) and the bog of Brobæk Mose (Insulinmosen) together cover 53 ha and are the largest contiguous wetland in Gentofte Municipality. Originally the lake was in use for commercial fishing, and examples of the old fishing houses can still be seen at the lake shore. Today it is more like a park lake with several reed islands in the western part. On the east bank is Folkeparken with many old trees. To the area belongs the small lake Langkær, which lies between the lake and Gentofte Church to the east. Brobæk Mose west of the lake was previously known as Insulinmosen, as it was owned by Nordic Insulin Laboratory. The natural forest in the bog is left untouched, allowing the natural development of new growth as well as old felled trees are preserved. Efforts are made to preserve the open areas south of the bog (Gentofte Enge), where many rare plants occur. The entire nature area except for Folkeparken is an EU protected area. 14 ha (the northern half of Folkeparken and the northern part of Brobæk Mose) are also protected.
The above description has been made by caretaker Thomas Vikstrøm and Joy Klein (DOF/BirdLife Danmark). The description of bird life below is written by Frank Desting.
The area has a rich bird life both in terms of breeding birds and migratory birds in as well as summer and winter guests. Of breeding birds by the lake can be mentioned Great Crested Grebe, Mute Swan, Greylag Goose , Mallard, Common Pochard, Tufted Duck, Eurasian Moorhen, Eurasian Coot, Northern Lapwing, Bearded Tit, Short-toed Treecreeper, Common Redstart, Reed Warbler, Marsh Warbler, Lesser Whitethroat, Greater Whitethroat, Common Starling, Greenfinch and Reed Bunting. In the bog Sparrowhawk, Common Buzzard, Cuckoo, Great Spotted Woodpecker, Eurasian Jay, Marsh Tit, Eurasian Nuthatch, Long-tailed Tit, Eurasian Treecreeper, Short-toed Treecreeper, Song Thrush, Thrush Nightingale , Blackcap, Garden Warbler, Willow Warbler, Common Chiffchaff, Hawfinch, European Goldfinch, Bullfinch and Chaffinch.
Summer guests include Lesser Black-backed Gull, Caspian Tern, Sandwich Tern and Common Tern are seen on a regular basis. In winter, especially during frost periods, Brobæk Mose (Brobækken) is known for freely exposed foraging Water Rail in the spring of the bog, in addition can which occasionally Woodcock and Grey Wagtail are seen. Great Bittern and Tawny Owl are also observed in the area. Northern Goshawk can also be seen hunting in the area occasionally, and flocks of Bohemian Waxwing can also be seen in the winter months. On the lake are often seen Whooper Swan, various ducks, including both Goosander and also Smew now and then.
During the migration season many exciting bird species are seen, both resting and migrating over the area, this applies to, for example Great Egret and various geese and ducks. A beautiful Red-crested Pochard male has also 'consulted' the lake on and off in recent years.
There is also a nice bird of prey migration over the area with many Common Buzzard, European Honey-buzzard, occasionally spiced up withRough-legged Buzzard, Red Kite, Black Kite, White-tailed Eagle, Peregrine Falcon, Marsh Harrier, Hen Harrier, Osprey (often foraging!) - and Eurasian Hobby, Merlin and even Red-footed Falcon! Large flocks of Common Crane are seen migrating over the area every year, especially in east wind. Wading birds are not seen many of which lack some open wading surfaces where the birds can forage, but some Common Sandpiper, Green Sandpiper, Snipe can be seen regularly. Furthermore, a flock of Grey Plover is noted pulling over the lake. Common Raven is regular. Common Kingfisher is regular, both in the bog and along the lake and White-throated Dipper is also noted a few times.
Many different birdspecies pass the area during the migration season, various larks, pipits and various finches - and there are the occasional Whinchat, Northern Wheatear, Spotted Flycatcher and Pied Flycatcher as well as Goldcrest in the migration season. It can also be mentioned that Red-backed Shrike and Great Grey Shrike are also listed in the area. A big sensation was when on 10/11 2019 I found a new species for the country in Folkeparken by Gentofte Lake, namely Taiga Flycatcher! More about this find can be read in 'BIRD YEAR 2019' published by DOF/BirdLife Danmark.
The nearest S-train station is at Gentofte. From here, there is a walk of about 500 meters to the northern end of the locality. Bus 184 (which runs between Nørreport Station and Holte Station) stops at Sønderbakken, Søbredden and Brogårdsvej, right up to Gentofte Sø & Brobæk Mose. Buses 171, 176 and 179 also run past Brogårdsvej at the north end of the lake. If you come by car, you can park on one of the roads around the lake. There are toilets next to the jetty on the south-east bank of the lake. A 5 km long path leads all the way round the lake and through Brobæk Mose.