This paper deals with an investigation into the metallurgy of the iron used in the erection of the Parthenon. The investigation covers the smelting of iron ore and deals extensively with the iron processes after smelting. Representative samples of Parthenon iron (two dowels and two clamps) have been studied by metallographic, mechanical, and chemical testing. The paper takes full account of ancient Greek writing dealing with ferrous metallurgy and the work of previous investigators. The methods of laying the dowels and clamps into the stones and of making the clamps have also been examined. Finally, a design showing metal processing on an ancient Greek lekythos in the British Museum has been studied and interpreted.