If you head up Calle San José from Plaza de la Mina, you come to one of the city's finest baroque churches where the country's first liberal constitution was declared in 1812. The Cortés (Parliament) met here to reform the government, which at the time was under the control of Joseph Bonaparte, stooge of his brother Napoleon. Inside the oval-shaped interior, the main work of art, an Immaculate Conception by Murillo, is displayed over the main altar. The church is crowned by a vast cupola.