After several months away from Spain Jim and I could take the suspense no longer. We returned to Matienzo, our goal being to find where the water flows into lake Buttermere in the Toca la Vaca system.
Having had to walk away from the upstream sump in the Whitworth series in Torca La Vaca when we ran out of time on our previous visit to the Matienzo area both Jim and I were keen to return.