the beach for many of the local residents of the Alentejo, visited by the rural families of Beja and Santiago do Cacém. Until the early 1970s, Sines was a sheltered fishing village with a long commercial history of relations with cities in the Mediterranean; its large marina, along a breakwater, is the only marina between Setúbal and the Algarve, while the deep-sea port, commercial fishery and industrial depot have driven the economy of this area. In 1970, the government of Marcello Caetano initiated the grand industrial-port complex that would, along with the 1974 Revolution, energize the local economy. Consequently, the population exploded, while industry and commerce diversified, causing their own impacts. In the late 1970s, the arrival of immigrants and refugees from the Portuguese overseas provinces brought new social dynamics, which were later supplemented by foreign workers employed in the port and petrochemical industry. Geography Physical geography The municipalities territory is distinguished by three morphological structures: a coastal plain, the residual relief of the Sines Massif, and the eastern escarpment. The coastal plan (which occupies the major part of the municipality) slopes gradually from the interior and occupies an area of 3-12 kilometres cut by several water courses. Little remains of the Sines Massif, but from Monte Chãos to the Cape, there are elements of its morphology still present: the Sines promontory is relatively elevated from the sea, and limited by an abrupt escarpment, which slopes to the south until the Ribeira da Junqueira., where beaches and dunes predominate. But after the beach of Burrinho, it continues to be rugged until the vicinity of the island Pessegueiro, where beaches are also evident, while sheltered coves and mini-beaches, such as Porto Covinho, are inter-cut along the coastline. From the north of the city the coast is low sandy beach that extends to Tróia. From this coast, extensive dunes, particularly north of the mouth of Ribeira dos Moinhos dominate the landforms. The eastern escarpment, which is limited by the coastal plain forms part of the Serra do Cercal Massif (which rises 100–200 meters in altitude). The coast, which is physically rugged (the Sines Cape) is separated into two differentiated areas: a sandy northern section, and a rocky southern area of cliffs. Climate Sines has a Mediterranean climate (Köppen: Csb/Csa) with mild, wet winters and warm, dry summers. The cape of Sines, shown in the weather box below, has minimal diurnal temperature variation