The Community of Madrid is historically and predominantly Roman Catholic, though it has grown increasingly secular and diverse in recent decades.
**Key Religious Sites:** * **Almudena Cathedral:** The seat of the Roman Catholic Archdiocese of Madrid, uniquely featuring a neoclassical exterior and a vibrant, pop-art-influenced neo-Gothic interior. It sits directly adjacent to the Royal Palace. * **Basilica of San Francisco el Grande:** Known for possessing one of the largest church domes in Christianity and housing paintings by Goya and Zurbarán. * **Islamic Cultural Center of Madrid (M-30 Mosque):** The largest mosque in Spain, serving Madrid's significant Muslim population. * **Other Faiths:** The city also supports various Protestant congregations, Orthodox churches, and Jewish synagogues, reflecting its cosmopolitan demographics.