The Chiemsee was formed, like many other pre-alpine lakes, at the end of the last ice age about 10,000 years ago from a hollow carved out by a glacier (a Zungen becken). Originally the lake covered an area of almost 240 km�, which is about three times its present area. Within 100 years its area shrank to around 200 ha. Before 1904 the water level was lowered by about a metre. As a result, large areas of dry land were reclaimed
