Hjertestien in Ådalen - a 4.5 km walk in Frederikssund
Follow the approximately 4.5 km Hjertestien walking route through Ådalen in Frederikssund on Zealand. The route passes Sillebro Å, Grønlien’s former gravel pit and woodland, with places to pause along the way.

Sillebro Å has supplied fresh water to the area since Viking times. The nearby village of Udesundby was later absorbed into Frederikssund, and Udesundby Church remains a reminder of the older settlement.
A stream with a history
From the Middle Ages, the stream powered a watermill near the site of the town’s later cinema. The mill closed in the 1830s and was replaced by a Dutch-style windmill on nearby Møllebakken. The stream once followed a more winding course and marked the town’s southern boundary where it reached the fjord west of Jernbanegade/Roskildevej. Inland, it divided the parishes of Ude Sundby and Oppe Sundby and also formed a boundary with Sundby Lille.
Urban development has reduced the valley, but the walking route still gives you access to its landscape. Hjertestien passes through Grønlien’s former gravel pit and into the woodland named after the old Grønlien farm.
Follow the marked route
Start at the car park just beyond Ågade 16 and follow the Hjertestien signs. The walk is approximately 4.5 km, with benches and places for a picnic. Hjertestien means Heart Trail and is part of a Danish tradition of signed walking routes developed with the Danish Heart Foundation. This route was created with the former Forest and Nature Agency, Frederikssund Municipality and the foundation’s local committee.
Download the route map and walking leaflet. The route is not suitable for wheelchair users.
Facilities
- Marked-out routes
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