Mønsted Kalkgruber

Mønsted Kalkgruber is located at Mønsted south of Hjarbæk Fjord and west of Viborg. The limestone pits are caves in a layer of limestone close to the surface, where lime has been quarried for many centuries, among other things to produce mortar for building churches and monasteries.

For many centuries, local farmers ran the mining business until 1872, when the rights to the lime were sold to Mønsted Kalkværker. Lime quarrying activities continued at the mine until 1953.

In some places in Northern Jutland, the limestone is very close to the surface. This is due to a thick layer of salt in the subsoil beneath the limestone. The layer of salt was deposited at a time when the area was covered by a shallow sea. The salt has a low density compared to other deposited layers. Because of this, the salt 'floats' slowly to the surface, while the heavier layers 'sink' into the subsoil.

As the salt moves towards the surface, it pushes chalk and lime in front of it. When the salt layer reaches the groundwater, it doesn't rise any higher as the water dissolves it and carries it away. Only dissolved minerals remain, forming a gypsum scab on top of the salt layer. By the time the salt reaches this point, in some places it has pushed the chalk and limestone so high that it is only a few metres below the surface. Normally, these layers would be at a depth of around 4-500 metres. Mønsted Limestone Pit, Daugbjerg Limestone Pit and Tingbæk Limestone Pit are all such raised limestone layers.

The lime can be washed away with underground springs and seeping water, forming natural underground passages and caves. The underground passages can collapse, forming so-called sinkholes, where the surface soil suddenly disappears into a hole.

There are not many cave-dwelling animals in Denmark, but one species in particular has learned to exploit the constant temperature of caves. The limestone mines in Jutland are known for their large numbers of bats, which spend the winter in the caves' frost-free environment. In August, the bats gather in the caves to mate and then hibernate in the same place until spring, when they emerge again. The Mønsted limestone quarries are home to the common water bat and the rarer pond bat.

The mine is nowadays mostly known as a tourist attraction, where concerts are sometimes held in the beautiful, almost cathedral-like large rooms. But in fact the mine is still used industrially. Arla has rented a large part of the mine's corridor for ripening Riberhus pit cheese. The cheeses are left to mature for three weeks in the cool corridors, where the temperature never exceeds 8 degrees, while the humidity is constantly around 98%. This provides a perfect environment for ripening cheeses - so perfect that it pays to transport the cheeses down the cramped old mine galleries and turn them every week for three weeks until ripening is complete. Most of the cheeses are then exported to Germany.