It was built at the wish of the Caliph Abd-al Rahman III using the money bequeathed to him by his favourite, Al-Zahra, and was intended to be the capital of a new province of the Caliphate of Cordoba; ultimately, however the sacking of the palace-city lead it to be remembered as Old Córdoba. The Caliph Abd al-Rahman III was a great promoter of culture and a skilful politician who transformed his dominions into the most prosperous lands in the west at the time, comparable only with Baghdad and Byzantium. The Al-Zahara mosque has a practically rectangular floor plan. It was built on raked terraces which made use of the slope of the mountainside. Each terrace was separated from the others by walls, which divided the city into three parts. The palaces were in the upper part, the intermediate zone was predominantly a landscape of orchards and gardens, while and lower part was the site of the main mosque and the residential buildings. There are still remnants of tiled borders, paintings and columns in the composite and Corinthian styles. Visitors should not miss a visit to the two recently restored rooms. It was declared a National Monument in 1923.