Two other nearby churches worthy of note are the Iglesia de Santo Domingo on Santo Domingo and Iglesia San Augustin on Paseo Estado. Read La Ruta de las Iglesias Santiago Centro for more descriptions and photos of a number of churches.
The Municipalidad de Santiago, begun in 1785 under the direction of Joaquín Toesca, who was responsible for many of the city's neo-classical buildings, is a national monument. On the facade you'll see the Santiago Coat of Arms, a gift from the King Carlos V of Spain.
