The Estuary of Bilbao (Spanish: Ría de Bilbao / Basque: Bilboko Itsasadarra) lies at the common mouth of the rivers Nervion, Ibaizabal and Cadagua, that drain most of Biscay and part of Alava in the Basque Country, Spain. It is a large estuary long that extends from Bilbao to the Bilbao Abra bay, a widening that makes the final transition between river and sea. It hosts the port of Bilbao in all its extension though the Harbour Authority has recently restored most of the upper shores to Bilbao and other municipalities for their urban regeneration. The harbour is now being displaced to the exterior, to the coastline of Santurtzi and Zierbena.