The Mezquita-Catedral holds 856 columns of jasper, onyx, marble, and granite — a forest salvaged from Roman temples across Iberia and North Africa when Abd al-Rahman I began construction in 785. What started as a modest mosque expanded four times under successive caliphs, each phase adding aisles and ornament until the prayer hall stretched across 24,000 square metres. The striped horseshoe arches, alternating brick and stone, were not mere decoration but structural innovation: the double-tiered design allowed builders to raise the ceiling without sourcing taller columns. When Córdoba fell to Fernando III in 1236, the mosque became a cathedral, and in 1523 Charles V authorised insertion of a Renaissance nave through the centre — a decision he later regretted, remarking that they had destroyed something unique to build something commonplace. The Judería, Córdoba's medieval Jewish quarter, stretches west from the Mezquita through a lattice of whitewashed lanes barely wide enough for two people to pass. Calleja de las Flores frames the bell tower in a tunnel of geranium pots; Calle Judíos leads to the 14th-century synagogue, one of three surviving in Spain and the only one in Andalusia. Bronze plaques mark the homes of Maimonides and other Sephardic scholars who made Córdoba a centre of philosophy, medicine, and translation during the Caliphate. The neighbourhood's current form owes more to 20th-century preservation than to medieval layout — Franco-era planners demolished irregular structures and replanted courtyards to match a romanticised Moorish aesthetic — but the scale and street pattern remain legible. The Alcázar de los Reyes Cristianos, built in 1328 on the ruins of a Visigothic fortress and Umayyad palace, served as a military headquarters for the Reconquista, a tribunal seat for the Inquisition, and later a civil prison until 1951. Its gardens, redesigned in the mid-20th century, descend in terraces planted with citrus, cypress, and reflecting pools fed by Arab-era irrigation channels. The Torre de los Leones offers rooftop views across the Guadalquivir to the Roman bridge, a 16-arch span rebuilt multiple times but still following the 1st-century alignment. Together, the three monuments form a compressed index of Iberian power: Islamic engineering, Christian conquest, and Jewish intellectual life colliding within a half-kilometre radius. Córdoba Jewish Quarter Mosque and Alcázar tours now pair the Mezquita's interior with extended walks through the Judería and Alcázar gardens, offering a fuller picture than standalone cathedral entry. The route covers roughly two kilometres on foot, manageable in three to four hours with a guide.