The salt pans of O Ulló and Larache are the largest salt complex still preserved in Galicia. Its origins date back to the 16th century, although it was not until the 17th century that Antonio Mosquera Villar y Pimentel obtained a licence to "work salt". In 1694 they were transferred to the Jesuits of Pontevedra, who also built a farm where the inhabitants of the parishes of Vilaboa worked as labourers, salt workers and salt cart drivers.
In the 18th century the Jesuits were expelled from Spain and the salt works were abandoned, as the salt from Portugal, Andalusia and Brittany was sufficient to cover the demand in the Kingdom of Galicia. They were never exploited again.
Together with the bottom of the Vigo estuary, the salt pans of O Ulló and Larache are included in the Natura 2000 Network as a Special Protection Area for Natural Values of the European Union. The aim is to ensure their conservation by virtue of their natural, cultural, scientific, educational and scenic interest.