From 1922 until 1928 Castiglioni worked on the plaster casts for friezes and monumental sculptures for the Palacio Legislativo of Montevideo, Uruguay; these were shipped to Uruguay, and the bronze or marble sculptures were made there. In the Fascist era he worked on sculptures for war cemeteries and monuments to the dead of the First World War, including: the military memorial of Monte Grappa (1935) in the Veneto; the Tempio Ossario di Timau (1937) in the comune of Paluzza, Udine; the military ossuary of Caporetto, now Kobarid, Slovenia; and the war memorial of Redipuglia (1938) in the province of Gorizia. In 1941 he made the tomb of Pope Pius XI in the Vatican Grottoes.