Stock Photo - Silves Castle and the surrounding landscape, Silves, Portugal, 2009. With its red walls (since it was built out of red sandstone and dried mud) the imposing castle stands proudly on top of a hill, ringed by its fortified curtain walls and eleven turrets. Silves is a town on the Portuguese Algarve, in the district of Faro. It is located near a Roman bridge over the Ribeira de Arade and thus controls the river valley down to the coast. The town was occupied by the Moors in 713 and became part of the Ummayad kingdom under the Arabic name of Shilb. In the 10th century, it was one of the most important towns of western Al-Andalus. Silves became an independent taifa in 1027.