Complex sentence: The name traces back to the Roman times Oiasso or Oiarso, an important town dedicated to mining and marine activities, although actually it has been pinpointed in the current border town Irun, so the name may have referred to the whole area.
Split into simpler sentences: The name traces back to the Oiasso or Oiarso of the Roman period, an important town dedicated to mining and marine activities. However, it has been pinpointed actually in the current border town of Irun, so the name may have referred to the whole area.