ACONCAGUA, a small northern province of central Chile, bounded on the north by Coquimbo, east by Argentina, south by Santiago and west by the Pacific. Its area, including Valparaiso, annexed in 1928, is 18,598sq. kilometers. Pop. (1920) including territory added in 1928, was 437,312; the 1930 census found 463,544. The province is very mountainous, and is traversed from east to west by the valley of the Aconcagua river. The climate is hot and dry, the rainfall being too small to influence climatic conditions. The valleys are highly fertile, and where irrigation is employed large crops are easily raised. Beyond the limits of irrigation the country is semi-barren. Alfalfa and grapes are the principal products, and considerable attention is given to the cultivation of other fruits, such as figs, peaches and melons. The Valle de Quillota, through which the railway passes between Valparaiso and Santiago, is celebrated for its gardens. The Aconcagua river rises on the southern slope of the volcano Aconcagua, the highest mountain in South America (more than 23,000ft.), first flows east down a broad valley, or bay in the mountains, and enters the Pacific I 2m. N. of The river has a course of about 200M., and its waters irrigate the best and most populous part of the province. Two other rivers—the Ligua and Choapa—traverse the province, the latter forming the northern boundary line. The capital is the seaport, Valparaiso, which had a population of 193,205 in 1930. Other important cities are Villa del Mar (pop. in 49,488), Quillota (pop. in 1930, 14,859) and San Felipe, the former capital (pop. in 1930, 11,963). Santa Rosa is a principal but small station on the trans-Andine branch of the State railway. A second port is Los Vilos, whence a railway 4om. long runs north-east to the Choapa. Another line connects Cabildo, in the Ligua valley, with the State railway.