Borrevannet, is a 4 km long, nutrient-rich lake close to Horten town and the Oslofjord and which attracts many migrant water-birds during spring and autumn. It is bordered by cultivated fields, mixed woods, with spruce in the north and mature deciduous trees in the south where there is also a golf-course on the eastern side. At the southern end of the lake is Vassbånn, a marshy area with birch, willow scrub and reedbeds. Over 250 bird species have been recorded at Borrevannet and the observation tower is a good place to start a very-early morning to observe the lakes large population of Great Crested Grebe and other water-birds and reedbed species such as Reed Warbler and Reed Bunting but also European Marsh Harrier and occasionally Bearded Tit. However, it is the intense sound of many singing Thrush Nightingale that dominate here during late spring and early summer along with other singing passerines including Icterine Warbler, Marsh Warbler and possibly Common Rosefinch. Later in the morning can also be good here for observing migrating raptors. Occasionally if conditions prevail on the southern or western side of Vassbånn, Great Snipe, Dotterel and other scarce species may be found during spring migration time. Until recently a bird-ringing (bird-banding) project was active here during the autumn where several scarce species have been caught and ringed including Yellow-browed Warbler, Blyth's Reed Warbler and Barred Warbler. During winter the lake is frozen and almost devoid of birdlife but Bohemian Waxwing flocks are often seen along the aproach road just after the main gate.
Drive north from the roundabout at Borre towards Horten town and after passing Granly School on the left take the first turning on the left signposted Borrevannet Golf Club. Follow this road to the golf club carpark and park here. Walk south, past the golfkro (golf restaurant) on the left and just after the new housing flats on the right take the path signposted Golfsti (Nature Trail) which first runs west past the new housing flats. With the golf green on the right and farmland on the left. After a while the path will then turn north and then parallel to the lake and reedbeds which will eventually come into view. When the path enters the small wood known as Eidepark, turn left and walk down to the observation tower. A second observation place is found by continuing a short distance further on into Eidepark. This will give a slightly different angle view into Vassbånn and under certain light conditions may be better viewed from here.
Terrain and HabitatForest, Wetland, Lake, Agriculture, Reedbeds, Grassland, Scattered trees and bushes
ConditionsFlat, Swampy, Open landscape, High water possible
Is a telescope useful?Can be useful
Good birding seasonSpring, Autumn, Summer
Best time to visitSpring migration, Spring, Autumn, Autumn migration, Summer
RoutePaved road, Wide path, Narrow trail
Difficulty walking trailAverage walk
Accessible byFoot, Bicycle
Birdwatching hide / platformYes
1. Night walks and very early mornings are advised for finding interesting singing passerines and Thrush Nightingale's.
2. Under no circumstances should the golf course be crossed when it is in use.
3. It is possible to walk from the observation tower southwards along the rampart bordering the reedbed then westwards along the horse-riding track and finally westwards along the Vassbånn track until Hereford wood is reached. This is an excellent place to watch migrating raptors from late morning/midday when conditions prevail. The first part of this route is exceptional for singing passerines.
4. Suitable footwear is advisable for the wet and muddy conditions expected away from the main route from the parking place to the observation tower.
5. A visit to the observation tower during weekends at prime migration time you will probably meet others that can help with directions to intresting bird species present and good observation spots around Vassbånn.