On the coast of the city of Viana, there are several places where, in times past, various sea work activities were carried out. Varying from parish to parish, the maritime tasks, generally, were divided into the harvesting of seaweed, coastal fishing, as well as gathering of Henlow’s swimming crab, and fishing in fishgarths. The “seaweed and fishing harbours” identified by Antonio Arthur Baldaque da Silva in 1892 are marked on this map. In addition to this information, there are references to the existence of fishgarths in this geographical area.