¡Hola y bienvenido Vaelico!
I hope you enjoy your time here.
Celtic Iberia, Spain and Portugal, are very interesting and, I feel, often get overlooked somewhat in discussions of the Celtic world, especially outside academic circles. This is a shame because the Castro Culture, the enigma of Tartessian and the mythology itself – Míl Espáine came from Spain – are all indeed important to Celtic studies. It has been suggested that Q-Celtic or Goidelic languages are connected to the Celtic languages of pre-Roman Spain and Portugal, namely Gallaecian, so there may be something more to the old mythology than previously believed.
Some interesting articles on the Celtiberians can be found here, at the e-Keltoi electronic journal: