At the beginning of the 17th century a hermitage was established on the piece of land that is now the Plaza San Martín. It was called San Sebastián, and was dedicated to spiritual retirement (retiro). For that reason the barrio is called Retiro.
In 1801 the Plaza de los Toros was moved to Retiro from the barrio of Monserrat, with space for 10,000 spectators. In 1812 the then Colonel San Martín created the Regiment ‘Granaderos a Caballo’ that used as its base the demolished Plaza de los Toros.
In 1862 the monument to General San Martín was unveiled, created by Frenchman Louis Joseph Daumas. It was then the zone of salting houses and tanneries began to change (owing to the removal of these industries) into being a summer holiday spot.
In 1863 the Ferrocarril del Norte (Northern Railway) was opened, joining up the Central Station (L. N. Alem and B. Mitre) with the barrio of Belgrano, forming one of the precursors to the current railway system. The catastrophe of a large fire completely destroyed the railway installations, which were then rebuilt by English industry in 1914, in an operation considered to be one of the biggest metallic constructions in the world.
Towards 1878, owing to an increased immigration, a lodging for immigrants was built, which lasted until 1911. Its had 800 beds and was an obligatory stop for the newly arrived.
Big organizations began to base themselves close to the square: the Ministry of Foreign Relations and Culture (the Chancellery, 1936) and Palacio Paz, which from 1939 has been the seat of the Círculo Militar and its library.
In its natural evolution, the barrio of Retiro has conserved an important aspect of its original features such as its monuments and the old architecture, placing alongside them the current and the intrinsic character of each of its corners.