Iron key with elongated eye, solid key handle and cruciform beards in beard, key iron commodity founding iron, hand-forged key with typical elongated and flattened heart-shaped eye (handle) solid key handle (with socket wrench end) Collar consisting of single profile edges cruciform battens (horizontal and vertical) in key beard and asymmetrical keyhole cross-section archeology Rotterdam City triangle Delftsevaart hang-en-sluitwerk The object was excavated and found at the partial reclamation of the Delfsevaart for the purpose of making the lift over the Vaart in the summer of 1928.