Cubatão, city, eastern São Paulo estado (state), southeastern Brazil. It is situated on the Atlantic coastal lowlands 16 miles (26 km) northwest of the port of Santos. Created in 1948 from several municipalities of Santos, Cubatão has become one of the state’s principal banana producers as well as an important industrial centre. One of the largest petroleum refineries in the country is located in Cubatão, producing oil, asphalt, plastic, synthetic rubber, and propane and butane gas in addition to petroleum fuels. Cubatão also has a large steel plant and two major hydroelectric generating facilities. The negative result was initially industrial pollution, earning the area the name Valley of Death, but pollution controls and other environmental efforts cleaned up the city in the late 1980s and ’90s. The city is linked to Santos, of which it is an adjacent suburb, by highway, and both a highway and a railroad extend northward from Cubatão to São Paulo city, the state capital. Pop. (2010) 118,720.