What to see at the Mosque of Córdoba

The interior of the Mosque is understood through its structure: a prayer hall arranged in aisles with a double arcade resting on columns. Around 850 columns of jasper, onyx, marble, granite and porphyry are recorded, and Almanzor's extension brought the total to nineteen aisles from north to south with close to 600 arches.

The double arcade was a structural solution to gain height: a horseshoe arch below and a semicircular arch above. The original Visigothic columns were too low for the builders' needs, so they added piers without tearing down the earlier arches. For the alternating colour, red brick and yellow limestone voussoirs were used, creating the unique look of the forest of columns.

In the foundational mosque of Abd al-Rahman I (785), all the columns and capitals were reused from Roman and Visigothic buildings. Abd al-Rahman II (833-852) extended the arcades by eight more bays. Al-Hakam II (961) extended the hall 45 metres to the south. And Almanzor (987) extended the building eight aisles to the east, leaving the mihrab off-centre. In this last section the arches no longer combine brick and stone, but are made entirely of limestone painted red where needed: recent research using 3D laser scanning has confirmed that the average column diameter is 44 centimetres and the spacing between them is 315 centimetres, figures that differ from those found in earlier publications.

The mihrab sits within the maqsura space, at the centre of the qibla wall. This section is linked to the extension by Al-Hakam II (after the year 965) and was the first mihrab to lead into a small chamber rather than simply housing a niche in the wall: a horseshoe-arch entrance to an octagonal chamber covered by a shell-shaped dome.

This entire area is decorated with Byzantine mosaics on a gold and bronze background. The craftsmen came from Constantinople, sent by Emperor Nicephorus II Phocas between 963 and 969, using nineteen colours and glass-paste tesserae coated with a thin layer of gold. The whole scheme recreates the Celestial Garden.

The maqsura is crowned with three ribbed domes, the central one reaching 15.40 metres in height, with interlaced polylobed arches that appear nowhere else in the building.

This is the most recognizable Christian part of the tour. The Main Chapel, Transept and Choir form the large central block added during the cathedral period. Work began in 1523 at the proposal of Bishop Alonso Manrique and wasn't completed until 1607, passing through the hands of architects Hernán Ruiz I, Hernán Ruiz II and Juan de Ochoa.

The main altarpiece, in Mannerist style, was designed by Alonso Matías starting in 1618. Beneath the dome of the transept lies the tomb of Bishop Leopoldo de Austria, uncle of Charles V and the chief driving force behind the cathedral works.

The choir holds a set of stalls carved by Seville sculptor Pedro Duque Cornejo between 1748 and 1757 from mahogany imported from Cuba: 106 seats assembled without a single nail. Duque Cornejo devoted the last nine years of his life to this work and died two weeks before its unveiling.

The Patio de los Naranjos is the complex's former ablutions courtyard, an enclosed space 130 metres long by 50 metres wide, surrounded by porticoed galleries with six outer gates. It was built by Emir Hisham I in the 8th century and expanded during the mosque's successive building phases.

The Muslim courtyard gave way to the Christian courtyard in works carried out under Bishop Francisco de Reynoso (1597-1601), who arranged the rows of orange trees as a visual continuation of the columns in the prayer hall. Beneath the orange trees lies a large cistern that supplied water for the ablutions.

The Gate of Forgiveness is the best-known main entrance to the Patio de los Naranjos. It was completed in March 1377 by order of Henry II of Castile, who covered the entire cost of the work.

It is a large gate measuring 9.45 metres high by 1.93 metres wide, made of pine wood covered with bronze sheets decorated with interlacing and Kufic inscriptions, with two pointed arches framing a space topped by a Baroque dome. In the spandrels of the outer arch is the coat of arms of John I, which includes both Castile and Portugal.

Architect Sebastián Vidal renovated it in 1650 after the new bell tower was built.

Today's tower holds the complex's past within it: from the Muslim minaret to the Christian bell tower. Records show a minaret raised by Abd al-Rahman III in 951-952, over 40 metres tall, today embedded within the Christian tower.

The tower admired today was built between 1593 and 1617 by Hernán Ruiz III around the remains of the minaret, following an earthquake in 1589. It rises 54 metres, equivalent to a 16-storey building, making it Córdoba's tallest structure.

Later, Juan Sequero de Matilla added the clock section, and in 1664 Gaspar de la Peña placed a new dome at the top, topped by the figure of Saint Raphael, guardian of Córdoba, a work by Pedro de la Paz and Bernabé Gómez del Río.