Terrestrial Open-Air Salterns of the Iberian Peninsula
Marine salterns where salt for human consumption is produced by evaporation of seawater in coastal lagoons in France, on the Iberian Peninsula and the Balearic Islands have been widely publicised and are known to many travellers. However, information on terrestrial open-air salterns is hard to come by. Such saltworks on land are less common since the NaCl concentration of brine springs is frequently too low and the periods of bright sunshine are too short to facilitate the production of salt on a reasonable scale.
Two terrestrial open-air salterns still exist on the Iberian Peninsula: the Salinas de Añana in Northern Spain, the last remaining example of several salterns in that region, and the Salinas de Rio Maior in Central Portugal. While operations at the saltern in Spain have essentially ceased, the saltern in Portugal is still fully operational. Both salterns draw their fairly concentrated brine from the shallow caprock of salt diapirs. The Salinas de Añana, the oldest of its kind in Spain, has been exploited probably since the times of the Roman Empire, certainly since the Arabs occupied Spain. The existence of the Salinas de Rio Maior has been documented since the 12th century. The article describes the historical facilities and mode of salt production at these salterns, their history, economic environment, evolution of ownership and present state.