• The revitalisation of Igartza is linked to the production of iron. The iron industry was the most important economic activity in Gipuzkoa.
  • The old forge dates from the 14th-15th century, although little trace remains apart from the exterior round ovens (the charcoal remains found there date back to 1782).
  • In 1782 a new forge was built, with the aim of exporting iron to Europe, together with the forges found at Agorregi and Aia.
  • Iron ore was obtained from the mines of Zerain and Mutiloa.
  • At the end of the 19th century, innovations in steelmaking marked the end of the hydraulic forges, giving way to the era of the blast furnaces. Two members of the families that ran the forges, Domingo Goitia and Martin Usabiaga, created the “Fabrica de Hierro San Martin” (“San Martin Iron Factory”) with the help of Francisco de Arana. This factory was the second most important structure in the era of the blast furnaces, the most important being that of Galdakao.
  • From the Fabrica de Hierro San Martin, the factory of the major rolling stock manufacturing company CAF (Construcción de Auxiliar de Ferrocarriles) was later created.
  • As the Indar factory had been built on top of the old forge, the remains were preserved beneath the plant. Today, only the bases of the tools remain.