Around 18,000BC, during the Weichselian glaciation, a thick cover of ice stretched over Scandinavia,[2] which eventually receded from the islands around 9000BC.[3] Around 8000BC the highest peaks of the then submerged archipelago rose from the Baltic Sea.[4] The sea levels would alternate in the Baltic Sea,[5] but a land bridge to Åland never formed, indicating the first humans came by boat or over the ice.[5]