The dune landscape differs from the rest of the landscape in that it is formed by the wind. Some dunes are a thousand years old while others are only a few hundred years old, and in certain places the dunes change every year. In many places along the Jutland North Sea coast, the sea devours a piece of the dunes every year, which many holiday home owners have painfully experienced. In many places in Denmark coastal protection plantings were created by planting beach grass to hold the sand. This minimizes the drift of sand into the land, which in olden times caused great problems. Since there are no high mountains in Denmark, the many high dunes are excellent viewpoints, e.g. B. Denmark's highest dune, Blåbjerg, which is 64 m high. Although 64m is a lot in Denmark, it is quite low in relation to the dunes of the Sahara, which in some places are over 200m high. The dune landscape in Denmark is divided into three areas - the white dunes on the very outside, then the gray dunes and finally the brown dunes. The flora and fauna of the dunes change towards the interior.