Dating to the 9th and 10th centuries, this rare jewel of a mezquita (mosque) perches a five-minute walk above Almonaster's main square. The almost perfectly preserved structure is like a miniature version of Córdoba's great mosque. Despite being Christianised in the 13th century, it retains nearly all its original Islamic features: the horseshoe arches, the semicircular mihrab (reputedly the Iberian peninsula's oldest), an ablutions fountain and various Arabic inscriptions. Even older are the Roman and Visigothic columns nearest the mihrab.
The original square minaret adjoins the building. Just below is Almonaster's 19th-century bullring.