The spring salt mines from which these unique salts come are the only Iberian salt mines that have survived to this day. This has been thanks to a salt generation tradition that has been passed from parents to children and that has remained unchanged in its artisanal production system, sustainable and respectful with the environment. Salt-making masters from Don Diego salt mines have worked for generations in the management and maintenance of the intangible heritage of the interior salt mines.
Salinas spring of Salinas Don Diego, have their origin in a sea that goes back to 200 million years ago, during the Late Triassic. In those times, the western half of the Iberian Peninsula was covered by the Sea Keuper or also called Sea Tethys. This one, underwent cyclical processes of evaporation and re-flooding, so that it was forming a thick saline layer on the ground. Tectonic movements ended up removing this thick layer, which was fragmented and in the subsoil. In this thick fragmented layer is the origin of the indoor natural salt mines from which salts of Don Diego salt mines are extracted.