The Giralda (Spanish: La Giralda) is a former minaret that was converted to a bell tower for the Cathedral of Seville in Seville. The tower is 104.5 m (343 ft) in height and it was one of the most important symbols in the medieval city. The tower was begun under the architect Ahmad Ben Baso in 1184. After Ben Baso's death, other architects continued work on the tower. The mathematician and astronomer Jabir ibn Aflah (or Geber) is also often credited with the tower's design. The tower was completed March 10, 1198 with the installation of copper spheres on the tower's top. Architects designed similar towers in what are now Spain and Morocco during this period. The tower of the Koutoubia Mosque in Marrakesh served as a model for the Giralda and its sister, the Hassan Tower in Rabat. The tower's first two-thirds is a former minaret from the Berber Almohad period of Seville, the upper third Spanish Renaissance architecture. After Seville was taken by the Christians (1248) in the Reconquista, the city's mosque was converted to a church. This structure was badly damaged in a 1356 earthquake, and by 1401 the city began building the current cathedral, one of the largest churches in the world and an outstanding example of the Gothic and Baroque architectural styles. The tower survived the earthquake, but the copper spheres that originally topped the tower fell during a 1365 earthquake, and the spheres were replaced with a cross and bell. The new cathedral incorporated the tower as a bell tower and eventually built it higher during the Renaissance under architect Hernán Ruiz, who was commissioned to work on the tower in 1568. This newer section of the tower contains a large inscription of Seville's motto, NO8DO, meaning "[Seville] has not abandoned me." Alfonso X of Castile gave the motto to the city when it continued to support his rule during an insurrection. Covering the top of the tower is the "Lily section" which surrounds the enclosure with the bell. The statue stands 4 m (13 feet) in height – 7 m (23 ft) with the pedestal – and sat on top of the tower from its installation in 1568 until 1997, when it was replaced with a copy. These towers, most notably those in Lebrija and Carmona, are popularly known as Giraldillas. Many towers have borrowed from the Giralda's design throughout history. Several church towers in the province of Seville also bear a resemblance to the tower, and may have been inspired by the Giralda. Numerous replicas of the Giralda have been built in the United States: one, now destroyed, in the second Madison Square Garden in New York City, designed by Stanford White, and another in Kansas City. The clock tower of the Ferry Building in San Francisco is also based on the Giralda. The clock tower at the University of Puerto Rico's Río Piedras campus was also inspired by the Giralda, as was the clock tower of the Railroad Depot in Minneapolis, destroyed by wind in 1941. The Biltmore Hotel in Miami, Florida, in the Coral Gables suburb, built in 1926, is a close replica of the Giralda. The Wrigley Building in Chicago is based on the tower as well. In popular literature, the Giralda plays a significant role in the 1998 Dan Brown novel Digital Fortress.