Bagsværd Lake is part of the Mølleå system, which extends from the source close to Roskilde Fjord to the outlet at Øresund. Bagsværd Sø is the second largest lake in the system, with an area of approx. 116 ha and the largest depth of 3.5 m. It has previously functioned as a mill pond. Today the lake is a popular excursion place where you can sail and fish. Since the 1930s, the lake has been used for rowing internationally. The nature in and around Bagsværd Lake is varied and interesting. Breeding birds, in recent years are Great Crested Grebe, Grey Heron (colony at Ellesumpen / Radiomarken), Mute Swan, Greylag Goose, Northern Goshawk (at Frederiksdal Skov), Common Buzzard, Eurasian Kestrel (at Radiomarken), Tawny Owl, Cuckoo, Great Spotted Woodpecker, Fieldfare (colony at Aldershvile Castle Park), and many other songbirds, tits, Short-toed Treecreeper , Common Raven and Common Starling and woodpeckers. In the summer Common Tern and sometimes Sandwich Tern and Caspian Tern are seen.
During spring and autumn a lot of migratory birds are seen over the lake. Whooper Swan and Barnacle Goose are seen regularly. Of birds of prey European Honey-buzzard, Red Kite, Rough-legged Buzzard, White-tailed Eagle, Osprey, Peregrine Falcon and Hen Harrier can be seen. In easterly winds, flocks of Common Crane pass the lake. In the winter, you often see Common Goldeneye, Great Crested Grebe and Common Raven. Occasionally, flocks of Common Redpoll, Bohemian Waxwing and Hawfinch appear. There are good chances of seeing Common Kingfisher. It can be observed in several places around the lake, but especially behind Aldershvile Nursery. Random guests such as Black Woodpecker and Lesser Spotted Woodpecker have also been seen at Bagsværd Lake several times. A rarity as Great Reed Warbler has also visited the lake, with up to two singing birds in the spring / summer respectively. years 2000 and 2011.
The nearest S-train station is Bagsværd Station. If you come by car, there are several parking options around the lake. It is possible to walk or bike all the way around the lake (7 km, see the route on the map below). Special nature areas include Aldershvile Castle Park, Radiomarken and Sophienholm.