Many small sand dunes are being formed on the beach between Raversijde (Ostend – West Flanders) and Middelkerke. These sand dunes are growing spontaneously because sand accumulates around plants such as marram grass and sea rocket. In the past, spontaneously growing dunes and plants were cleared away using beach cleaning machines. But this is no longer the case because today it is appreciated that these dunes are useful for retaining sand and protecting the coast against storms and flooding.