A great deal of time ago, the marshes were seen as zones of scarce value, but the science has shown that they are one of the richest ecosystems of the planet. These marshes constitute the main humid zone of the Cantabrian cornice. They occupy 3.866 hectares distributed among the municipal terms of Argoños, Bárcena of Cicero, Colindres, Escalante, Laredo, Clean, Noja, Santoña and Voto. This singular spot, besides plenty of marine fauna, is utilized for the migratory fowls coming from the north, in its displacement toward warmer lands. In this natural space have been observed, up to date, more than 121 species of aquatic fowls.

This protected space is 38 square kilometres, and encompasses the entire Bay of Santoña and its estuaries, as well as the Buciero Massif and the nearby Joyel and Victoria wetlands, located around Noja. This is one of the most important wetlands of the Iberian Peninsula, a key stop on the migratory routes of many species of birds, as well as being one of the most varied and interesting sections of the Cantabrian coast, combining different types of coastal landscape: cliffs, beaches and dunes, estuaries and wetlands.

THE VICTORIA MARSHES:
The Victoria Marshes are the most humid and oriental zone of the municipality, it has 151 hectares of surface. It is an important ecological area.

THE JOYEL MARSHES:
The Joyel Marshes are located in an aquifer, they occupy the northwestern area of Noja. It has an extension of 249 hectares.
Here, the ruins of another mill of tides are found.