Until the 18th century the port of Betanzos was one of the most important fishing and trade centre of the Ancient Kingdom of Galicia. The river sediment that filled the estuary and reduced its depth was one cause, among others, for the decrease in sea traffic. The Ría de Betanzos currently has one of the largest areas of coastal mudflats of Galicia, and still has a small port and embarkations at the confluence of the Mendo and Mandeo rivers which hug the town. The riverbanks form the other part of this protected space which, in the case of the Mandeo, covers 25 kilometres upriver.
The best observatory of this wetland is on the access road which runs along the left margin of the estuary. Here, we will find the pazo of Mariñán (Bergondo) where, during visiting hours, we can visit the gardens where there are five tree taxa, catalogued as Singular Trees. There are inland routes to Chelo (Betanzos), where, apart from the nature workshop, the routes into the forests lining the river Mandeo begin. The course of the river speeds up at times among the granite outcrops o this stretch, providing beautiful vignettes against the rhythm of the waters.