On the coast and part of the Barcelona
conurbation in the most westerly sector.
It includes the lower valley of the river Llobregat,
from the Cairat gorge to the foot of Montserrat,
down to the mouth, where it forms a small delta
(alluvial plain of La Marina and lagoons at El Prat
de Llobregat). The Ordal sierras
and the Garraf massif
rise in the eastern sector along the borders. In
the Middle Ages, the territory was part of the so-called
outlying areas of Barcelona and came under important
lordly jurisdictions, such as the barony of Castellbell
de Rosanes or the monastery of Montserrat.
The economy had traditionally been based on agriculture,
but the expansion of the Barcelona area has transformed
it, both by introducing industry and drawing it within
the residential belt of the metropolis. Tourism is
particularly important on the coast (Castelldefels,
Gavà, Viladecans).
