Tartessos or Tartessus, was a semi-mythical harbor city and the surrounding culture on the south coast of the Iberian Peninsula, at the mouth of the Guadalquivir River. It appears in sources from Greece and the Near East starting during the first millennium BC. Herodotus, for example, describes it as beyond the Pillars of Heracles. Roman authors tend to echo the earlier Greek sources but from around the end of the millennium there are indications that the name Tartessos had fallen out of use and the city may have been lost to flooding, though several authors attempt to identify it with cities of other names in the area. Archaeological discoveries in the region have built up a picture of a more widespread culture, identified as Tartessian, that includes some 97 inscriptions in a Tartessian language.
The Tartessians were rich in metal. In the 4th century BC the historian Ephorus describes "a very prosperous market called Tartessos, with much tin carried by river, as well as gold and copper from Celtic lands". Trade in tin was very lucrative in the Bronze Age, since it is an essential component of true bronze and is comparatively rare.