Already in 1248, shortly after the reconquest of the city by the Christians, the original mosque was consecrated as a cathedral. After the earthquake of 1356 much of the original mosque had collapsed but some parts survived, including the minaret, now the lower section of the cathedral's famous bell tower - the Giralda - and the Patio de los Naranjos, a large courtyard.Construction of the new church started in 1402 after a design by Alonso Martínez and the building was completed in 1517, however work on the interior continued until the early 20th century. The cathedral is one of the world's largest. The interior is enormous and boasts five large naves. The building is 126 meter long and 83 meter wide (413 x 272 ft), with a ceiling height of up to 37 meter (121 ft).