Tijuana,city, northwestern Baja California Norte estado (“state”state), northwestern Mexico. The city lies along the Tecate River near the Pacific Ocean and is 12 miles (19 km) south of San Diego, Calif., U.S. It originated as a ranch settlement on part of a land grant (1862) and developed as a border resort with gambling casinos. In the 20th century it became the main entry point to Mexico from California for American tourists, and tourism remains its most important economic activity. From 1950 to the mid-1990s Tijuana’s population increased more than tenfold.

Many American-owned maquiladoras (assembly plants) opened in the area from the 1960s. Other manufactures include food products, soft drinks, and beer. Vast areas of surrounding farmland were opened up for the cultivation of wheat, barley, and wine grapes through irrigation schemes, which contribute to the city’s shortage of potable water, much of which is supplied via aqueduct from the Colorado River. The city is easily accessible by railroad, highway, and air from the southwestern United States and from many points in Mexico. Pop. (19802005) 429,500; (1990) 698,752urban agglom., 1,484,005.