This is a fishing system in the form of a stone structure built in the 16th century by the Cistercian monks. It can only be seen at low tide and during spring tides. Today, only the lower part of the structure remains, due to a severe storm that struck the Galician coast in 1979. The construction stretches across the harbour inlet, and the central opening was once closed with a wooden gate. It was used as a fishing system, so that when the tide came in, the gate remained open, and when the tide began to go out, it was closed, leaving the fish and shellfish trapped between the camboa and the beach.