The URDAIBAI Biosphere Reserve lies in a sheltered spot on the Bay of Biscay coast, in the Busturialdea district of the province of Bizkaia, one of the “historical territories” of the Basque Autonomous Community. With its cliffs and beaches, its woods and inland rivers, its marshes and its river plains, URDAIBAI probably has a greater diversity of landscape and environments than any other part of the Basque Country. It has a mild, humid, ocean climate characterised by mild variations in temperature, rainfall spread evenly throughout the year and little frost..
