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.