The Biscayan Estuary

In the province of Biscay, between Cape Matxitxaco and Cape Ogoño, is a stretch of 12 kilometres of sand that was declared a Biosphere Reserve by UNESCO in 1984, along with many other ecosystems. Holm oak forests emerge only a few metres away from the aquatic vegetation, which gives an idea of the estuary's environmental diversity.

The Urdaibai estuary constitutes one of the richest natural areas in the Basque Country. Mountains of moderate height, yet quite steep, lead to a valley that ends in the Cantabrian Sea forming a wide estuary. The flats become salt marshes in some areas, while they form cliffs and beaches in others. Thus, numerous biotypes and ecosystems coexist, the wetlands being particularly remarkable since they are listed in the Ramsar Agreement and were declared a Special Bird Protection Area. This varied wetland comprises holm oak forests, thickets, moors, rocky areas and diverse aquatic fauna. In the areas affected by human presence are man-made forests, meadows and farmed lands that also constitute the habitat of a great number of plant and animal species. There are more than 600 species in this reserve, many of which are part of the remarkable Cantabrian holm oak forests. As for local fauna, birds have the largest colonies, since this wetland is on the migratory path of a myriad of bird species. This ornithological diversity includes both sedentary and breeding birds. More than 300 vertebrates have been classified in this Biosphere Reserve. One of them, the European mink, is quite remarkable since it is a very rare species in the Basque Country.