Basílica de Nuestra Señora del Pilar, Zaragoza

Spain's largest baroque church and an important pilgrimage site, it's most famous for housing a pillar, which according to legend, the Virgin used as a conduit between heaven and earth in order to appear in person before Saint James the apostle. Pilgrims head directly to touch the pillar in the holy chapel on their pilgrimage, an impressive 18th-century structure built Ventura Rodríguez. The alabaster reredos sculpted by Damián Forment on the the main altarpiece in the 16th century are the church's greatest artistic treasure. It's also worth looking at the choir stalls carved in oak and boxwood and two frescoes painted by Goya during the 18th century. You get some marvelous views of the river and the city from the top of the towers.