According to
Manuel Sanchis Guarner, Castell de Ferro comes from the
Mozarabic autochthonous evolution that conserves
archaisms such as the non-
diphthongization of the Latin letter É. The survival of these archaisms, is explained by the greater fidelity to the Latin Andalusian
romance. It has been attempted sometimes to justify, without much foundation, the influence in the
toponomy of emigrants arrived after the
Christian conquest. This same phenomenon occurs in other names such as Ferreira or Poqueira, which are believed to have similarities with the
Galician language. A more likely explanation is that the change from "castil" to "castell" took place between the seventeenth and nineteenth centuries when large numbers of expats returned from Catalonia accompanied by Catalans. The word would have changed under the influence of the
Catalan language which allows for the LL digraph in final position, pronounced /ʎ/ as in
castell /kəs'teʎ/. ==History==