There are a few key indicators that can help you tell if wrought iron is vintage. First, look for any signs of rust or corrosion. If the iron is heavily rusted, it's likely quite old. Secondly, examine the iron for any maker's marks or stamps. These are often found on the underside of vintage pieces. Finally, consult an expert to get a definitive answer. An antique dealer or appraiser will be able to give you a more accurate idea of the age and value of the piece.