Dover with square button decorated in carving technique, three incised birds, damper heating earth finding ceramic earthenware, molded carved baked sgraffito Dover with square knob In the sides of the knob at the base, two triangles are cut out per side. Slanted sides Decorated in carving technique Decoration consists of lines that divide the sidewall into rough triangles between the lines of squeezed mespoints Three birds are incised on the underside. Red shard by heating discolored into gray pottery archeology Rotterdam City triangle Oostplein underground pit indigenous earthenware deaf fire room kitchen heating Soil discovery Rotterdam underground pit Oostplein from lower clay layer 1976.