Ravnkilden: A Living Ice Age Archive in Rold Forest

Ravnkilden spring is not only one of Denmark’s most beautiful springs – it is also a fascinating natural phenomenon with stories to tell from a distant past. You’ll find it at the foot of Rebild Bakker on the eastern side of Gravlev Valley, tucked away like a little gem surrounded by dense forest.

A spring with character

Ravnkilden is what is known as a marsh spring. This means that the water does not gush from one single point, but seeps up through the ground across a wider area before the many small streams gather into one flow.

There is an impressive force hidden beneath the surface: every single second, as much as 85 litres of crystal-clear water flows past the old ford on its way towards Lindenborg Å. Although it is tempting to feel the fresh water, the spring is protected, and wading in the source area itself is not allowed. Luckily, stones have been laid out so you can cross the spring with dry feet – and you are welcome to drink from it.

Nature’s own thermostat

One of the most magical things about Ravnkilden is its temperature. The water stays at 7–8°C all year round. This creates some truly special sights:

In winter: When frost bites, steam rises from the spring, and you can spot fresh green plants lighting up the white snow.
In summer: While the air is warm, the spring water feels refreshingly cool.

A haven for “climate refugees”

The constant temperature makes Ravnkilden a very special home for more than 200 different species of small animals. Here live what we might call nature’s “time travellers” – rare insects and tiny creatures that migrated to Denmark in the periods following the Ice Age.

Some prefer the cold, others the warmth, but they all survive here in the spring because the water never becomes too warm in summer or too cold in winter compared with the rest of the country.

Find the spring: On the Danish Nature Agency’s map, the spring is marked as point of interest (2). There are good parking options in the car parks along Hulvejen. Ravnkilden is one of the experiences on the official Rebild Bakker route.