What is "schwanenstein"

The Schwanenstein is a glacial erratic on the island of Rügen in Germany. It lies about 100 metres east of the harbour at Lohme on the northern shore of the Jasmund peninsula about 20 metres off the beach in the Baltic Sea. It weighs 162 tonnes and has a volume of 60 m³. It is thus the fifth largest erratic of about 20 other large glacial boulders that are part of Rügen’s legally protected geotopes. It is stylistically portrayed in Lohme’s coat of arms.