Why do we associate the Swedish coasts with bare, steep rocks and with fiords, while the Polish beaches are built of soft sand and cliffs? Who or what had ‘dug ‘ the Baltic basin? Where the amber comes from? These and other questions will be answered during the class on the Baltic Sea geology. We will use microscopes to have a closer look at different types of rocks and to compare their structure. We will check what happens if we pour the hydrochloric acid on a rock and find out why it is good to sometimes take a magnet for a walk to the beach.