Pilar

Originally located on the flood-prone banks of the Luján River, the small town of Pilar and its chapel were relocated to their current site in the 1800s. Pilar was the site of the signing of the Treaty of Pilar in 1820, a foundational document that is one of "pre-existing pacts" of the Constitution of Argentina and laid the foundation for Argentina's federal system of government.

Since the 1990s, Pilar has undergone a demographic transformation fueled by the development of gated communities within and around the city limits. In recent decades, as the administrative center of Pilar Partido, the city has diversified its economy, supported by neighbouring industries and a growing service sector in the district. As a result, Pilar has solidified its position as a development hub on the outskirts of Greater Buenos Aires.