The Baltic Sea island of Vilm lies in the bay south of the much larger island of Rügen, it is one of Germany's most remote and tranquil spots. Covering less than 1 km², Vilm is the remnant of a moraine left as the glaciers retreated about 6000 years ago. Since its formation the shape of the island has gradually changed, with sandbars and beaches forming and eroding continuously. Today the island is shaped like a 2.5 kilometre-long tadpole, consisting of two distinct parts. Great Vilm, the "head" to the north-east, rises to almost 40 m. The low-lying isthmus of Middle Vilm forms a long "tail" to the south-west, which culminates in Little Vilm, a rocky mound about 20 m above sea level. The chalky cliffs to the southern side of Great Vilm are rapidly eroding, while sandbanks are building to add a snail-like curl to the tail.