In Sifnos, exploitation of the subsoil (silver, gold, and iron mining) took place beginning in prehistoric times, which has left visible marks on the island. So, there are two metalliferous zones in the positions of Agios Sostis, Agios Sylivestros, Voreini, Kapsalos and Xeroxylo, and in the area of Agios Giannis of Faros and in Aspros Pyrgos. It has been proven that the silver mine in Agios Sostis started operating at the beginning of the 3^rd millennium BC and is the most ancient silver mine in the world.