Bahia Blanca, a city and port of Argentina, on the Naposta river, 3 m. from its outlet into a deep, well-sheltered bay of the same name. Pop. (est. 1903) 11,600. It is situated in the extreme southern part of the province of Buenos Aires and is 447 m. by rail S.W. of the national capital. The opening to settlement of the national territories of La Pampa and Neuquén has contributed largely to the growth and importance of Bahia Blanca. It is the natural shipping-port for these territories and for the southern districts of the province of Buenos Aires, from which great quantities of wheat and wool are exported. The bay has long been recognized as one of the best on the Argentine coast, and when the channel is properly dredged, will admit steamers of 30 ft. draught at low-water. The Argentine government has located its principal naval station here, at the Puerto Militar, between the city and the entrance to the bay. The port, whose trade is increasing rapidly, is connected with the neighbouring and interior producing districts by five or six lines of railway and their branches. Bahia Blanca dates from 1828, when a fort and trading post were located here, but its development as a commercial centre began only in 1885, when its first railway line was opened.
In 1908 direct railway communication was opened with Mendoza and San Juan. Though situated near the mountainous section of southern Buenos Aires, the immediate vicinity of the city is low and swampy, its water is brackish, and it has been decidedly unhealthy; but a water supply from the Sauce Grande, 50 m. distant, was projected in 1906, and this, with better drainage and street paving, was expected to improve matters. The mean annual temperature is 60°, and the average annual rainfall is 19 in. The city has street cars, electric-lights and telephone service, and the port has a shipping pier 1640 ft. long, with spacious warehouses and several miles of railway sidings.