Built in 1855, the soaring twin spires of the basilica pierce the sky and are visible all the way from Signal Hill. Its design marks the revival of classical architecture in North America. Inside, 65 unique stained-glass windows illuminate the remarkable polychromatic Italianate ceiling and its gold-leaf highlights. The honor of being named a 'basilica' was bestowed on the church by Pope Pius XII on its centennial anniversary. Free half-hour tours are offered 10am to 5pm Monday to Saturday in July and August, according to demand.