Urdaibai is the only biosphere reserve in the Basque Country.
The estuary is home to the European mink, one of the most endangered carnivores on the continent.
Laida beach is a dynamic sandbar that expands and contracts significantly depending on tidal cycles.
The reserve includes the Santimamiñe Cave, which contains Upper Paleolithic cave paintings.
The Oka river valley acts as a natural corridor for bird migration, attracting over 200 species annually.
The Ogoño rock formation is a massive limestone cliff rising directly from the sea, utilized by nesting raptors.
The area features a salt marsh system that acts as a natural water filtration mechanism for the estuary.
It is a primary site for the study of the Atlantic salmon's river recolonization in Spain.
Urdaibai Biosferaren Erreserba is a UNESCO-designated wetland reserve centered on the Oka River estuary in the Basque Country. The area encompasses 220 square kilometers of diverse ecosystems including tidal marshes, riverbanks, and coastal cliffs. It serves as a critical stopover point for migratory birds traveling between Europe and Africa. The geography ranges from the Ogoño headland cliffs to the extensive sandbanks of Laida and Laga beaches. Permanent human settlements like the fishing village of Mundaka and the town of Gernika-Lumo lie within its boundaries. The reserve is characterized by a high degree of landscape heterogeneity shaped by oceanic tides. It remains an active site for ecological research and conservation of the European mink. Visitors can access various observation points to view both marine and terrestrial wildlife.
The panoramic viewpoint above the Laida beach sandbar near the Ibarrangelu area.
Check the tide charts before visiting, as many paths and sandbanks become inaccessible during high tide.
Bring binoculars for birdwatching, as species concentrations vary significantly between the inner marshes and outer coastline.
Stick to marked trails to avoid damaging sensitive nesting habitats or fragile salt marsh vegetation.
Do not attempt to walk across the mudflats when the tide is rising, as it creates hazardous conditions.
Maintain silence near bird nesting areas; do not leave any waste behind; do not disturb local livestock or wildlife.
