Wooden object with rectangular hole in the middle, butterfly-shaped, artifact soil find wood, sawn stabbed Wooden object with open rectangular hole in the middle Butterfly shaped with dent or notch on one end. Clear wood grain in the longitudinal direction of the object. Light green varnish layer archeology Rotterdam City center Stadsdriehoek Groenendaal underground pit construction close Soil discovery Rotterdam underground pit Groenendaal from the 15th to the 16th century layer 1975-09-26.