The document provides a historical overview and architectural description of the Mosque-Cathedral of Córdoba in Spain. It details how the site began as a mosque built in the 8th century on top of a Christian church, and was later converted into a cathedral in the 13th century after Córdoba was captured by King Ferdinand III. The document describes the architectural elements of the building like its hypostyle hall with over 800 columns, horseshoe arches, and decorative materials like marble, mosaics and tilework representing the blending of Muslim and Christian styles over its evolution. It highlights the UNESCO World Heritage site as a symbol of the cultural tensions between Christians and Muslims in medieval Spain.