Sylacauga (sĭləkŏgˈə) [key], city (1990 pop. 12,520), Talladega co., central Ala.; inc. 1839. It is a processing center for a livestock and timber area. The city is built upon a solid bed of cream-white marble, which has been quarried since 1840. Textiles, clothing, metal goods, fertilizers, and dairy items are also produced. Nearby is Flagg Mountain, which was a signal relay station during the Civil War.