The northwest corner of Calles 23 and 12, one block north of Cementerio Colón, marks the spot where on April 16, 1961, Castro announced (on the eve of the Bay of Pigs invasion) that Cuba was henceforth socialist. The anniversary of the declaration of socialism is marked each April 16, when Castro speaks here. The facade bears a bronze bas-relief showing Fidel surrounded by the heroes who were killed in the U.S.-sponsored strike on the airfield at Marianao that was a prelude to the invasion.