Playa de la Arena, Beach in Biscay, Spain

Playa de la Arena is a dark-sand beach shared by the municipalities of Zierbena and Muskiz, between the settlements of La Arena and Pobeña at the mouth of the Barbadun river. It measures 966 metres long, covering 343,382 m² at low tide and 86,382 m² at high tide, with the Petronor refinery installations nearby.

The dunes behind the beach and along the Barbadun estuary cover 10.4 hectares, the largest area of semi-natural dunes in the Basque Country. Access roads and car parks damaged the wind-blown sand system, but since the 1980s the Biscay Provincial Council, the councils of Zierbena and Muskiz and the Spanish Government have restored and enlarged it.

The beach lies between the neighbourhoods of La Arena, in Zierbena, and Pobeña, in Muskiz, and takes its name from the dark sand. Behind the sand and along the Barbadun river mouth stretch dunes covering 10.4 hectares, the largest area of dunes in the Basque Country still in a semi-natural state.

La Arena stretches 966 metres along the Barbadun estuary between Pobena (Muskiz) and the La Arena district of Zierbena, with Petronor's facilities nearby. At low tide the sand covers 343,382 m², shrinking to 86,382 m² at high tide, so the waterline shifts a long way; time a visit accordingly. The dunes behind the beach, covering 10.4 ha, are the largest semi-natural dune area in the Basque Country.

The Barbadun estuary behind the beach is part of the Natura 2000 conservation network and shelters rare wading and migratory birds that can be spotted from the sand itself. This combination of a swimming beach next to a protected wetland is rare along this coastline.