How could a rock formed by volcanic activity get to this shoreline, surrounded by sedimentary rocks? That was the question a group of third-grade students asked--and answered--during an inquiry-based summer camp. Over a two week timeframe, the students practiced basic inquiry skills such as observing; measuring; describing and drawing; sharing tasks in a team; and applying physical principles to field observations along the Baltic Sea coast in northern Germany. Through this activity, common rocks in the children's environment obtained new meaning for them, and at the same time, scientific skills of observation and reasoning were strengthened. (Contains 4 figures and 2 online resources.)