The discovery of a remarkable group of vividly coloured rounded cobbles in the fields and monuments of the later medieval outports of Bruges has initiated a multi-disciplinary investigation into their function, provenance, and wider economic meaning. Geological analyses demonstrate that the stones are ballast of exotic lithological nature. A substantial number consist of glacial erratics collected from cobble beaches in the Baltoscandian area. Another group can be traced to north-eastern British coasts. The clustering of stones at Hoeke has drawn particular attention to the Hanseatic connection with Bruges and to the small harbour town of Hoeke, which hosted the staple of stockfish and various other Hanseatic activities. This article contributes to the discussion of ballast stones as a meaningful archaeological object category, especially when studied in a broader methodological context including archaeological, geological, and historical research.