Llobregat Delta Nature · el Prat de Llobregat, Baix Llobregat, Barcelona The Llobregat delta is a 98 km² alluvial plain formed at the mouth of the river, between the Garraf massif and Montjuïc, shared between the Baix Llobregat and Barcelonès counties, very close to the city of Barcelona. It is the second largest delta in Catalonia and is considered of international importance by the European Union, which declared it a Special Area of Conservation in 2014. The present-day delta is the result of a marine transgression that occurred in the Holocene, with sands, gravels and silts that have advanced toward the sea over some 6,000 years. Different habitats coexist within it, from the sandy beach and coastal pine forest to market-garden and fruit crops, wastelands and some wetlands with brackish-water lagoons, concentrated in the areas closest to the coast. Photo: Jordiferrer (CC BY-SA 3.0) What to see and do in el Prat de Llobregat