Zamboanga (sāmˌbōängˈgä) [key], city (1990 pop. 442,345), Zamboanga del Sur prov., SW Mindanao, the Philippines, at the tip of the Zamboanga peninsula, on Basilan Strait. One of the chief cities of Mindanao and a busy seaport, it is the hub of a major iron-producing and lumbering area, which has large-scale rubber cultivation, plywood mills, and resin plants. The city is situated at the foot of high mountains. Although it is in a mostly Muslim area (see Moros), the city is predominantly Christian. Points of interest include a 16th-century Spanish fort and the mosque at Talangkusay, a famous Moro ceremonial center. The city has at times been the scene of fighting between Muslim Moro rebels and government forces.