 This hypothesis is supported by the existence of an ancient olive press in nearby Santo Stefano Belbo, and by the fact that olives continue to thrive there, although not in any great quantity, to the present day.The first human settlers to the area came from Liguria, but the first extant buildings and documentary evidence of settlement date from Roman times.Tradition has it that the four towers, now collapsed, of the present castle were built by the Romans.