This complex is located on what was once the seventh and final southern block of the city, founded in 1580 by Juan de Garay. It was not the southern boundary by chance, but because a stream ran through that block, one of the three that carried water from the city's upper reaches to the Río de la Plata

With a mere 2.5 meters of frontage, this house, which was part of a dwelling from the second decade of the 19th century, is known as the narrowest in the city. It has a simple facade, consisting of a two-leaf door with green-painted panels and, on the upper floor, a small balcony with iron bars. These houses were for freed slaves, to whom their masters assigned a small space to build their living quarters, adjacent to their property. The house on San Lorenzo Passage—the only one of its kind remaining in Buenos Aires—measures 2.5 meters wide and 13 meters deep.