Teatro Municipal, Opera house in San Nicolás de los Arroyos, Argentina.

The Teatro Municipal is an opera house in San Nicolás de los Arroyos featuring Italian horseshoe-shaped architecture reminiscent of early 20th-century European theaters. Inside, marble staircases, Austrian Thonet furniture, and painted ceilings create an elegant interior.

Construction began in 1906 and finished in 1908, with the opening featuring Puccini's Manon Lescaut opera. The building later became a national historical monument, reflecting Argentina's connection to European opera culture.

The theatre's name honours Rafael de Aguiar, founder of San Nicolás, and was given in 1958 for the venue's 50th anniversary; a bronze plaque in the hall records it. From 1952 to 1955 it was officially called Eva Perón. The building also houses the municipal Culture Department office, and the corner bar open since 1933 was known for its secret-recipe drink El San Martín.

The building stands at the corner of De la Nación and Maipú streets and is easy to locate. Visitors should take time to explore the entrance areas and foyer, as these are decorated with the same care as the main hall.

The painted drop curtain was made by scenographer Mateo Casella in Naples, on the same canvas used for the Teatro Colón's curtain. The hall's ceiling and curtain carry paintings by Italian artist Rafael Vicente Barone, and a red cloth over one ceiling figure shows two shades of bordeaux, which gave rise to local legends.