The name of some of the castles and oppida are known through the declaration of origin of persons mentioned in epitaphs and votive Latin inscriptions ("Berisamo, Letiobri, Ercoriobri, Louciocelo, Olca, Serante, Talabriga, Aviliobris, Meidunio, Durbede.."), through the epithets of local Gods in votive altars ("Alaniobrica, Berubrico, Aetiobrigo, Viriocelense"...), and the testimony of classic authors and geographers ("Adrobrica, Ebora, Abobrica, Nemetobriga, Brigantium, Olina, Caladunum, Tyde, Glandomirum, Ocelum..."). Some more names can be inferred from modern place names, as those containing an evolution of the Celtic element "brigs" meaning "hill" and characteristically ligated to old hill-forts ("Tragove, O Grove < Ogrobre, Canzobre < Caranzobre, Cortobe, Lestrove, Landrove, Iñobre, Maiobre"...) Approximately half the pre-Latin toponyms of Roman Gallaecia were Celtic, while the rest were either non Celtic western Indo-European, or mixed toponyms containing Celtic and non-Celtic elements.