Every spring, more than 10 000 cranes rest at Lake Hornborga. Most of them spend the winter in Extremadura in southern Spain. They begin in returning to Lake Hornborga in mid-March. Their journey takes them through France and the Rhine Valley. Their last stop before Lake Hornborga is the island of Rügen in northen Germany. The number of cranes reaches its peak between 10-20 April when there are 5000 to 7000 cranes at Naturum Trandansen at Bjurum, at the southern part of the lake.