In the past, the park's area was a Baltic Sea bay. The sea's activity, however, created sand dunes which in the course of time separated the bay from the Baltic Sea. As waves and wind carry sand inland the dunes slowly move, at a speed of 3 to 10 metres per year. Some dunes are quite high - up to 30 metres. The highest peak of the park – Rowokol ( above sea level) – is also an excellent observation point. The "moving dunes" are regarded as a curiosity of nature on a European scale.