Brace yourself for this great baroque cavern of Catholicism. The faithful believe that here on 2 January AD 40, the Virgin Mary appeared to Santiago (St James the Apostle) atop a pilar (pillar) of jasper, and left the pillar behind as a testament to her visit. A chapel was built around the pillar, followed by a series of ever more grandiose churches, culminating in the enormous basilica.
A lift whisks you most of the way up the basilica's northwest tower from where you climb to a superb viewpoint over the domes and city.
Originally designed in 1681 by local architect Felipe Sánchez y Herrera, the basilica was greatly modified in the 18th century by the royal architect Ventura Rodríguez, who added the ultra-baroque Santa Capilla at the east end (housing the legendary pillar), and the flurry of 10 colourfully tiled mini-domes that surround the main dome on the roof.
The famous pillar is topped by a 15th-century Gothic sculpture of the Virgin and child, and is concealed inside an elaborate silver casing which is itself usually three-quarters hidden by the long mantle in which the Virgin image is dressed (except on the 2nd, 12th and 20th of each month). A tiny oval-shaped portion of the pillar is exposed in the passage on the chapel's outer west side and a steady stream of people line up to brush lips with its polished and cracked cheek, which even popes have air-kissed. Parents also line up from 1.30pm to 2pm and 6.30pm to 7.30pm to have their babies blessed next to the Virgin. More than the architecture, these sacred symbols, and the devotion they inspire, are what make this church special.
Hung from the northeast column of the Santa Capilla are two wickedly slim shells that were lobbed at the church during the civil war. They failed to explode. A miracle, said the faithful; typical Czech munitions, said the more cynical.
The basilica's finest artwork is the 16th-century alabaster retablo mayor (main altarpiece) by Damián Forment, facing west in the middle of the basilica. There are also two Goyas: La Adoración del Nombre del Dios, on the ceiling of the coreto (small choir) at the church's far east end, is an early classical piece from 1772; vastly different is Regina Martirum painted above the north aisle in 1780 (in the third cupola from the east). With its blurry impressionistic figures, it was hugely controversial at the time.