At 'the mouth' ('la boca') of the Riacheulo River, is a brightly colored neighborhood, whose history began in the 16th century. Juan de Garay, from the Basque Country of Spain, sailed to the South American continent on a number of exploratory expeditions and founded cities along the way, including the 'second' foundation of Buenos Aires in 1580. (I'm not entirely clear how you can found a city for a 'second' time, but so the history websites say...)
The area of this second founding was primarily a port that sustained a neighborhood of humble houses and grocery stores. When ship trade increased in the 1800s, the neighborhood expanded with immigrants, who asked the shipyards for leftover paint to color the exterior walls of their houses and businesses.
The colorful neighborhood became famous, and, as with all interesting poor areas of town, it soon attracted artists and bohemians. By the end of the 1900s, La Boca had shifted to a tourist attraction with a rich history, although the hints of poverty are still visible, and the locals still recommend only visiting La Boca during daylight hours.
If the building had a fresh coat of paint and served cafe con leche or sold souveniers, we assumed it was part of the tourism industry. If the building was older with chipping paint and was only accessible through the narrow alleyways, we assumed it was a remnant of the immigrant/bohemian neighborhood.
The buildings with creepy plaster figures hanging out the window we avoided. This particular creeper is a prostitue, commemorating the brothels that used to be (perhaps still are?) a part of La Boca.